Lennox SL280DFV User Manual

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INSTALLATION

 2011 Lennox Industries Inc.

Dallas, Texas, USA

DOWNFLOW

INSTRUCTIONS SL280DFV

DAVE LENNOX SIGNATURE COLLECTION GAS FURNACE DOWNFLOW AIR DISCHARGE

506710−01 06/2011 Supersedes 01/2011

THIS MANUAL MUST BE LEFT WITH THE

HOMEOWNER FOR FUTURE REFERENCE

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a licensed professional installer (or equivalent), service agency or the gas supplier.

Litho U.S.A.

AIR FLOW

CAUTION

As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.

This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to the potential for personal injury or death.

Table of Contents

Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Parts Arrangement 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SL280DFV Gas Furnace 4. . . . . . . . . . . . . . . . . . . . . . . . .

Shipping and Packing List 4. . . . . . . . . . . . . . . . . . . . . . . .

Safety Information 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Use of Furnace as a Construction Heater 5. . . . . . . . . . .

General 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Combustion, Dilution & Ventilation Air 6. . . . . . . . . . . . . .

Setting Equipment 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Filters 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Duct System 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Venting 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas Piping 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

06/11

*2P0611*

Page 1

NOTICE

A thermostat is not included and must be ordered separately.

 The Lennox icomfort Touch thermostat must be

used in communicating applications.

 In non−communicating applications, the Lennox

ComfortSense well as other non−communicating thermostats.

In all cases, setup is critical to ensure proper system operation.

Field wiring for both communicating and non−communicating applications is illustrated in diagrams, which begin on Page 23.

Electrical 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Integrated Control Settings 32. . . . . . . . . . . . . . . . . . . . . . .

Blower Performance Data 35. . . . . . . . . . . . . . . . . . . . . . . .

Unit Start−Up 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas Pressure Adjustment 40. . . . . . . . . . . . . . . . . . . . . . . .

Proper Combustion 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

High Altitude 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Other Unit Adjustments 42. . . . . . . . . . . . . . . . . . . . . . . . . .

Heating Sequence of Operation 42. . . . . . . . . . . . . . . . . . .

Service 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Planned Service 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Repair Parts List 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Integrated Control Diagnostic Codes 48. . . . . . . . . . . . . . .

Program Unit Capacity/Size Mode 55. . . . . . . . . . . . . . . . .

Troubleshooting 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7000 thermostat may be used, as

506710−01

*P506710-01*

Unit Dimensions − inches (mm)

3−1/8

(79)

9/16

(14)

RETURN AIR

OPENING

FLUE OUTLET

(Top)

19−7/16

9/16

(14)

(494)

9/16

(14)

TOP VIEW

9/16

(14)

1−1/2 (38) Front Panel

27−3/4 (7705)

19−7/16

(494)

9/16

(14)

ELECTRICAL INLET

(Either Side)

GAS PIPING INLET

(Either Side)

19−1/4

Supply

(489)

Air

Supply

Air

(838)

5−3/8 (137) Right 2−1/8 (54) Left

6−5/8 (168) Right 7−1/8 (181) Left

3/4

(19)

FRONT VIEW SIDE VIEW

Model No.

SL280DF070V36A 14−1/2 368 13−3/8 340 13 330 4−3/4 121 SL280DF090V48B

SL280DF090V60C SL280DF110V60C

17−1/2 446 16−3/8 416 16 406 6−1/4 159

A B C D

in. mm in. mm in. mm in. mm

21 533 19−7/8 504 19−1/2 495 8 203

Page 2

Parts Arrangement

CONTROL BOX

(Includes two−stage integrated control,

transformer and circuit breaker)

INTERNAL FLUE PIPE ASSEMBLY

GASKET

FLUE CHASE

BLOWER ASSEMBLY

SECONDARY LIMIT

DOOR INTERLOCK SWITCH

ROLLOUT SWITCH

INNER BLOWER ACCESS PANEL

ACCESS PANEL

PRIMARY LIMIT LOCATION

HEAT EXCHANGER

COMBUSTION AIR INDUCER

PRESSURE SWITCHES

COMBUSTION AIR INDUCER

GAS VALVE

BURNER BOX ASSEMBLY

FIGURE 1

Page 3

SL280DFV Gas Furnace

The SL280DFV gas furnace is equipped with a two−stage, variable speed integrated control. the control is compatible with: Communicating thermostats − icomfort Touch Non−communicating thermostats − ComfortSense or other conventional thermostats. Control systems − Harmony III Zone Control System (non−communicating). Each SL280DFV unit is shipped ready for installation in the downflow position.

Shipping and Packing List

Package 1 of 1 contains

1 − Assembled SL280DFV unit 1 − Bag assembly containing the following:

2 − Screws 1 − Snap bushing 1 − Snap plug 1 − Wire tie 1 − Vent warning label 1 − Owner’s manual and warranty card

The following items may be ordered separately: 1 − Thermostat 1 − Propane/LP changeover kit 1 − Combustible flooring base

Check equipment for shipping damage. If you find any damage, immediately contact the last carrier.

Safety Information

DANGER

Danger of explosion.

There are circumstances in which odorant used with LP/propane gas can lose its scent. In case of a leak, LP/propane gas will settle close to the floor and may be difficult to smell. An LP/propane leak detector should be installed in all LP applications.

WARNING

CAUTION

As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.

Certifications

SL280DFV units are CSA International certified.

In the USA, installation of gas furnaces must conform with local building codes. In the absence of local codes, units must be installed according to the current National Fuel Gas Code (ANSI-Z223.1). The National Fuel Gas Code is available from the following address:

American National Standards Institute, Inc. 11 West 42nd Street New York, NY 10036

Clearances

Adequate clearance must be made around the air openings into the vestibule area. In order to ensure proper unit operation, combustion and ventilation air supply must be provided according to the current National Fuel Gas Code.

Vent installations must be consistent with the venting tables (in this instruction) and applicable provisions of local building codes.

This furnace is CSA International certified for installation clearances to combustible material as listed on the unit nameplate and in the tables in figure 13. Accessibility and service clearances must take precedence over fire protection clearances.

Installed Locations

For installation in a residential garage, the furnace must be installed so that the burner(s) and the ignition source are located no less than 18 inches (457 mm) above the floor. The furnace must be located or protected to avoid physical damage by vehicles. When a furnace is installed in a public garage, hangar, or other building that has a hazardous atmosphere, the furnace must be installed according to recommended good practice requirements and current National Fuel Gas Code.

NOTE − Furnace must be adjusted to obtain a temperature rise (high and low fire) within the range(s) specified on the unit nameplate. Failure to do so may cause erratic limit operation and may also result in premature heat exchanger failure.

This SL280DFV furnace must be installed so that its electrical components are protected from water.

Installed in Combination with a Cooling Coil

When this furnace is used with cooling units, it shall be installed in parallel with, or on the upstream side of, cooling units to avoid condensation in the heating compartment. With a parallel flow arrangement, a damper (or other means to control the flow of air) must adequately prevent

Page 4

chilled air from entering the furnace (see figure 1). If the damper is manually operated, it must be equipped to prevent operation of either the heating or the cooling unit, unless it is in the full HEAT or COOL setting.

GAS UNIT

Dampers

(open during heating

operation only)

AIR HANDLER

Dampers

(open during cooling

operation only)

FIGURE 1

When installed, this furnace must be electrically grounded according to local codes. In addition, in the United States, installation must conform with the current National Electric Code, ANSI/NFPA No. 70. The National Electric Code (ANSI/NFPA No. 70) is available from the following address:

National Fire Protection Association 1 Battery March Park Quincy, MA 02269

NOTE − This furnace is designed for a minimum continuous return air temperature of 60°F (16°C) or an intermittent operation down to 55°F (13°C) dry bulb for cases where a night setback thermostat is used. Return air temperature must not exceed 85°F (29°C) dry bulb.

The SL280DFV furnace may be installed in alcoves, closets, attics, basements, garages, and utility rooms in the downflow position.

This furnace design has not been CSA International certified for installation in mobile homes, recreational vehicles, or outdoors.

Use of Furnace as Construction Heater

Lennox does not recommend the use of SL280DFV units as a construction heater during any phase of construction. Very low return air temperatures, harmful vapors and operation of the unit with clogged or misplaced filters will damage the unit.

SL280DFV units may be used for heating of buildings or structures under construction, if the following conditions are met:

D The vent system must be permanently installed per

these installation instructions.

D A room thermostat must control the furnace. The use of

fixed jumpers that will provide continuous heating is not allowed.

D The return air duct must be provided and sealed to the

furnace.

D Return air temperature range between 60°F (16°C) and

80°F (27°C) must be maintained.

D Air filters must be installed in the system and must be

maintained during construction.

D Air filters must be replaced upon construction comple-

tion.

D The input rate and temperature rise must be set per the

furnace rating plate.

D One hundred percent (100%) outdoor air must be pro-

vided for combustion air requirements during construction. Temporary ducting may supply outdoor air to the furnace. Do not connect duct directly to the furnace. Size the temporary duct following these instructions in section for Combustion, Dilution and Ventilation Air in a confined space with air from outside.

D The furnace heat exchanger, components, duct system,

air filters and evaporator coils must be thoroughly cleaned following final construction clean−up.

D All furnace operating conditions (including ignition, in-

put rate, temperature rise and venting) must be verified according to these installation instructions.

General

These instructions are intended as a general guide and do not supersede local codes in any way. Consult authorities having jurisdiction before installation.

In addition to the requirements outlined previously, the following general recommendations must be considered when installing a SL280DFV furnace:

 Place the furnace as close to the center of the air dis-

tribution system as possible. The furnace should also be located close to the chimney or vent termination point.

 Do not install the furnace where drafts might blow direct-

ly into it. This could cause improper combustion and unsafe operation.

 Do not block the furnace combustion air openings with

clothing, boxes, doors, etc. Air is needed for proper combustion and safe unit operation.

 When the furnace is installed in an attic or other insu-

lated space, keep insulation away from the furnace.

NOTE − The Commonwealth of Massachusetts stipulates these additional requirements:

D Gas furnaces shall be installed by a licensed plumb-

er or fitter only.

Page 5

D The gas cock must be T handle" type.

D When a furnace is installed in an attic, the passage-

way to and service area surrounding the equipment shall be floored.

WARNING

Product contains fiberglass wool.

Disturbing the insulation in this product during installation, maintenance, or repair will expose you to fiberglass wool. Breathing this may cause lung cancer. (Fiberglass wool is known to the State of California to cause cancer.)

Fiberglass wool may also cause respiratory, skin, and eye irritation.

To reduce exposure to this substance or for further information, consult material safety data sheets available from address shown below, or contact your supervisor.

Lennox Industries Inc. P.O. Box 799900 Dallas, TX 75379−9900

Combustion, Dilution & Ventilation Air

In the past, there was no problem in bringing in sufficient outdoor air for combustion. Infiltration provided all the air that was needed. In today’s homes, tight construction practices make it necessary to bring in air from outside for combustion. Take into account that exhaust fans, appliance vents, chimneys, and fireplaces force additional air that could be used for combustion out of the house. Unless outside air is brought into the house for combustion, negative pressure (outside pressure is greater than inside pressure) will build to the point that a downdraft can occur in the furnace vent pipe or chimney. As a result, combustion gases enter the living space creating a potentially dangerous situation.

In the absence of local codes concerning air for combustion and ventilation, use the guidelines and procedures in this section to install SL280DFV furnaces to ensure efficient and safe operation. You must consider combustion air needs and requirements for exhaust vents. A portion of this information has been reprinted with permission from the National Fuel Gas Code (ANSI-Z223.1). This reprinted material is not the complete and official position of the ANSI on the referenced subject, which is represented only by the standard in its entirety.

CAUTION

Do not install the furnace in a corrosive or contaminated atmosphere. Meet all combustion and ventilation air requirements, as well as all local codes.

CAUTION

Insufficient combustion air can cause headaches, nausea, dizziness or asphyxiation. It will also cause excess water in the heat exchanger resulting in rusting and premature heat exchanger failure. Excessive exposure to contaminated combustion air will result in safety and performance related problems. Avoid exposure to the following substances in the combustion air supply:

Permanent wave solutions Chlorinated waxes and cleaners Chlorine base swimming pool chemicals Water softening chemicals De-icing salts or chemicals Carbon tetrachloride Halogen type refrigerants Cleaning solvents (such as perchloroethylene) Printing inks, paint removers, varnishes, etc. Hydrochloric acid Cements and glues Antistatic fabric softeners for clothes dryers Masonry acid washing materials

All gas-fired appliances require air for the combustion process. If sufficient combustion air is not available, the furnace or other appliances will operate inefficiently and unsafely. Enough air must be provided to meet the needs of all fuel-burning appliances and appliances such as exhaust fans which force air out of the house. When fireplaces, exhaust fans, or clothes dryers are used at the same time as the furnace, much more air is necessary to ensure proper combustion and to prevent a downdraft. Insufficient air causes incomplete combustion which can result in carbon monoxide.

In addition to providing combustion air, fresh outdoor air dilutes contaminants in the indoor air. These contaminants may include bleaches, adhesives, detergents, solvents and other contaminants which can corrode furnace components.

The requirements for providing air for combustion and ventilation depend largely on whether the furnace is installed in an unconfined or a confined space.

Unconfined Space

An unconfined space is an area such as a basement or large equipment room with a volume greater than 50 cubic feet (1.42 m bined input rating of all appliances installed in that space. This space also includes adjacent rooms which are not separated by a door. Though an area may appear to be unconfined, it might be necessary to bring in outdoor air for combustion if the structure does not provide enough air by infiltration. If the furnace is located in a building of tight construction with weather stripping and caulking around the windows and doors, follow the procedures in the air from outside section.

) per 1,000 Btu (.29 kW) per hour of the com-

Page 6

Confined Space

A confined space is an area with a volume less than 50 cubic feet (1.42 m

) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in that space. This definition includes furnace closets or small equipment rooms.

When the furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space containing the furnace, the return air must be handled by ducts which are sealed to the furnace casing and which terminate outside the space containing the furnace. This is especially important when the furnace is mounted on a platform in a confined space such as a closet or small equipment room. Even a small leak around the base of the unit at the platform or at the return air duct connection can cause a potentially dangerous negative pressure condition. Air for combustion and ventilation can be brought into the confined space either from inside the building or from outside.

EQUIPMENT IN CONFINED

CHIMNEY

OR GAS

VENT

FURNACE

NOTE − Each opening shall have a free area of at least one square inch (645 mm ing of all equipment in the enclosure, but not less than 100 square inches (64516 mm

) per 1,000 Btu (.29 kW) per hour of the total input rat-

SPACE ALL AIR FROM INSIDE

WATER

HEATER

OPENINGS

(To Adjacent

Room)

FIGURE 2

Air from Inside

If the confined space that houses the furnace adjoins a space categorized as unconfined, air can be brought in by providing two permanent openings between the two spaces. Each opening must have a minimum free area of 1 square inch (645 mm

) per 1,000 Btu (.29 kW) per hour of total input rating of all gas−fired equipment in the confined space. Each opening must be at least 100 square inches (64516 mm

). One opening shall be within 12 inches (305 mm) of the top of the enclosure and one opening within 12 inches (305 mm) of the bottom. See figure 2.

Air from Outside

If air from outside is brought in for combustion and ventilation, the confined space must have two permanent openings. One opening shall be within 12 inches (305 mm) of the top of the enclosure and one opening within 12 inches (305 mm) of the bottom. These openings must communicate directly or by ducts with the outdoors or spaces (crawl or attic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch (645 mm

) per 4,000 Btu (1.17

kW) per hour of total input rating of all equipment in the enclosure. See figures 3 and 4. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch (645 mm

) per

2,000 Btu (.56 kW) per total input rating of all equipment in the enclosure. See figure 5.

When ducts are used, they shall be of the same cross−sectional area as the free area of the openings to which they connect. The minimum dimension of rectangular air ducts shall be no less than 3 inches (75 mm). In calculating free area, the blocking effect of louvers, grilles, or screens must be considered. If the design and free area of protective covering is not known for calculating the size opening required, it may be assumed that wood louvers will have 20 to 25 percent free area and metal louvers and grilles will have 60 to 75 percent free area. Louvers and grilles must be fixed in the open position or interlocked with the equipment so that they are opened automatically during equipment operation.

Page 7

CHIMNEY OR

GAS VENT

FURNACE

(Inlet Air from Crawlspace and Outlet Air to Ventilated Attic)

VENTILATION LOUVERS

(Each end of attic)

EQUIPMENT IN CONFINED SPACE

ALL AIR FROM OUTSIDE

OUTLET

AIR

WATER

HEATER

CHIMNEY

OR GAS

VENT

FURNACE

VENTILATION

LOUVERS

(For unheated crawl space)

NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.

INLET

AIR

FIGURE 3

EQUIPMENT IN CONFINED SPACE

ALL AIR FROM OUTSIDE

(All Air Through Ventilated Attic)

VENTILATION LOUVERS

(Each end of attic)

OUTLET

AIR

INLET AIR

(Ends 12 in.

above bottom)

FURNACE

CHIMNEY

OR GAS

VENT

CONFINED SPACE

WATER

HEATER

OUTLET AIR

INLET AIR

EQUIPMENT IN

ALL AIR FROM

OUTSIDE

WATER

HEATER

NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645 mm

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.

FIGURE 4

Page 8

NOTE − Each air duct opening shall have a free area of at least one square inch (645 mm

) per 2,000 Btu (.59 kW) per hour of the total input rating of all equipment in the enclosure. If the equipment room is located against an outside wall and the air openings communicate directly with the outdoors, each opening shall have a free area of at least one square inch (645 mm per 4,000 Btu (1.17 kW) per hour of the total input rating of all other equipment in the enclosure.

FIGURE 5

)

Downflow Installation

Downflow unit installs in three ways: on non−combustible flooring, on combustible flooring using a downflow combustible flooring base, or on a reverse−flow cooling cabinet. Do not drag the unit across the floor.

Installation on Non−Combustible Flooring (Figure 6)

CAUTION

The furnace and downflow combustible flooring base shall not be installed directly on carpeting, tile, or other combustible material other than wood flooring.

1 − Cut floor opening keeping in mind clearances listed on

unit rating plate. Also keep in mind gas supply connections, electrical supply, flue and air intake connections and sufficient installation and servicing clearances. See table 1 for correct floor opening size.

2 − Flange warm air plenum and lower the plenum into the

opening.

3 − Set the unit over the plenum and seal the plenum to

the unit.

4 − Ensure that the seal is adequate.

SL280DFV UNIT

OPENING

SUPPLY AIR

PLENUM

SL280DFV UNIT

SUPPLY AIR PLENUM

PROPERLY

SIZED FLOOR

OPENING

DOWNFLOW

COMBUSTIBLE

FLOORING BASE

FIGURE 7

TABLE 2

COMBUSTIBLE FLOOR OPENING SIZE

Cabinet Width

A (14.5")

B (17.5")

C (21")

NOTE − Floor opening dimensions listed are 1/4 inch (6 mm) larger than unit opening. See unit dimensions on page 2.

Front to Rear Side to Side

in. mm in. mm

22 559 15−3/4 400

22 559 18−3/4 476

22 559 22−3/4 578

FIGURE 6

TABLE 1

NON−COMBUSTIBLE FLOOR OPENING SIZE

Cabinet Width

A (14.5") 19−3/4 502 13−1/4 337

B (17.5") 19−3/4 502 16−1/4 413

C (21") 19−3/4 502 19−3/4 502

NOTE − Door opening dimensions listed are 1/4 inch (6 mm) larger than the unit opening. See unit dimensions on page 2.

Front to Rear Side to Side

in. mm in. mm

Installation on Combustible Flooring (Figure 7)

1 − When unit is installed on a combustible floor, a down-

flow combustible flooring base must be installed between the furnace and the floor. The base must be ordered separately.

See table 2 for opening size to cut in floor.

2 − After opening is cut, set combustible flooring base into

opening.

3 − Check sealing strips on combustible flooring base to

make sure they are properly glued and positioned.

4 − Lower supply air plenum into downflow combustible

flooring base until plenum flanges seal against the strips.

NOTE − Be careful not to damage sealing strips. Check for a tight seal.

5 − Set the furnace over the plenum.

6 − Ensure that the seal between the furnace and plenum

is adequate.

Installation on Cooling Cabinet (Figure 8)

1 − Refer to reverse−flow coil installation instructions for

correctly sized opening in floor and installation of cabinet.

NOTE − Downflow combustible flooring kit is not used

2 − When cooling cabinet is in place, set and secure the

furnace according to the instructions that are provided with the cooling coil. Secure the furnace to the cabinet.

3 − Seal the cabinet and check for air leaks.

Page 9

PROPERLY

SIZED FLOOR

OPENING

SL280DFV UNIT

COOLING COIL

PLENUM

Setting Equipment

WARNING

Do not install the furnace on its front, back or in the horizontal position. See figure 12. Do not connect the return air ducts to the back of the furnace. Doing so will adversely affect the operation of the safety control devices, which could result in personal injury or death.

Install the SL280DFV gas furnace as shipped in the downflow position only. Do not install the furnace hori-

zontally.

FIGURE 8

Return Air Opening −− Downflow Units

The following steps should be taken when installing plenum:

1 − Bottom edge of plenum should be flanged with a

hemmed edge (See figure 9).

PLENUM

SECURE FROM

OUTSIDE CABINET

Side View

HEMMED EDGE

SEALING STRIP

(Field Provided)

CABINET SIDE PANEL

FIGURE 9

2 − Sealing strip should be used.

3 − In all cases, plenum should be secured to top flanges

of furnace with sheet metal screws.

SECURE FROM IN-

SIDE CABINET

PLENUM

Side View

HEMMED EDGE

Select a location that allows for the required clearances that are listed on the unit nameplate. Also consider gas supply connections, electrical supply, vent connection, and installation and service clearances [24 inches (610 mm) at unit front]. The unit must be level.

NOTE − Units with 1/2 hp blower motors are equipped with three flexible legs and one rigid leg. See figure 11. The rigid leg is equipped with a shipping bolt and a flat white plastic washer (rather than the rubber mounting grommet used with a flexible mounting leg). The bolt and washer must

be removed before the furnace is placed into operation. After the bolt and washer have been removed, the rig-

id leg will not touch the blower housing.

SL280DFV07036A WITH 1/2 HP

BLOWER MOTOR

RIGID LEG

remove shipping bolt and washer

FIBERGLASS SEALING STRIP (Field Provided)

CABINET SIDE

PANEL

FIGURE 10

4 − In closet installations, it may be impossible to install

sheet metal screws from the outside. In this case,

make plenum with a removable front and install

screws from the inside (See figure 10).

5 − Make certain that an adequate seal is made.

FIGURE 11

WARNING

The blower access panel must be securely in place when the blower and burners are operating. Gas fumes, which could contain carbon monoxide, can be drawn into living space resulting in personal injury or death.

Page 10

Front

Back

FIGURE 12 Downflow Application Allow for clearances to combustible materials as indicated on the unit nameplate. Minimum clearances for closet or alcove installations are shown in figure 13.

Downflow Application Installation Clearances

Top

Left Side

Bottom

Type of Vent

Connector

Top 1 in. (25 mm) 1 in. (25 mm)

*Front 2−1/4 in. (57 mm)** 2−1/4in. (57 mm)

Back 0 0

Sides 0† 0

Vent 6 in. (152 mm) 1 in. (25 mm)

Floor NC†† NC††

*Front clearance in alcove installation must be 24 in. (610 mm). Maintain a minimum of 24 in. (610 mm) for front service access. ** 3−1/4 in. if single wall vent pipe is used. †Left side requires 3 in. if a single wall vent is used on 14 −1/2 in. cabinets, or 2 in. if a single wall vent is used on 17 − 1/2 in. cabinets. ††The furnace may be installed on a combustible wood floor if an optional additive base is installed between the furnace and the combustible floor.

Type C Type B1

Right Side

FIGURE 13

Horizontal

WARNING

Improper installation of the furnace can result in personal injury or death. Combustion and flue products must never be allowed to enter the return air system or the living space. Use screws and joint tape to seal the return air system to the furnace. In platform installations with bottom return air, the furnace should be sealed airtight to the return air plenum. A door must never be used as a portion of the return air duct system. The base must provide a stable support and an airtight seal to the furnace. Allow absolutely no sagging, cracks, gaps, etc. The return and supply air duct systems must never be connected to or from other heating devices such as a fireplace or stove, etc. Fire, explosion, carbon monoxide poisoning, personal injury and/or property damage could result.

Filters

This unit is not equipped with a filter or rack. A field−provided high−velocity filter is required for the unit to operate properly. Table 3 lists recommended filter sizes. A filter must be in place any time the unit is operating.

TABLE 3

Cabinet Width

A (14−1/2") 14 x 25 x 1 (1) B (17−1/2") 16 x 25 x 1 (1)

C (21") 20 x 25 x 1 (1)

Return Air Filter Size (inches)

Page 11

Duct System

Use industry-approved standards (such as those published by Air Conditioning Contractors of America or American Society of Heating, Refrigerating and Air Conditioning Engineers) to size and install the supply and return air duct system. This will result in a quiet and low-static system that has uniform air distribution.

NOTE − Do not operate the furnace in the heating mode with an external static pressure that exceeds 0.8 inches w.c. Higher external static pressures may cause erratic limit operation.

Ensure that you have made a seal between the supply air plenum and the furnace and between the furnace and the return air plenum.

Return Air Plenum Return air must not be drawn from a room where this

furnace, or any other gas−fueled appliance (i.e., water heater), or carbon monoxide−producing device (i.e., wood fireplace) is installed. When return air is drawn

from a room, a negative pressure is created in the room. If a gas appliance is operating in a room with negative pressure, the flue products can be pulled back down the vent pipe and into the room. This reverse flow of the flue gas may result in incomplete combustion and the formation of carbon monoxide gas. This toxic gas might then be distributed throughout the house by the furnace duct system.

Venting

A 4−inch diameter flue transition is factory-installed on all models. Modifying or removing the flue transition will

cause the unit to operate unsafely and will void the unit certification. The vent connector does not require insula-

tion. The SL280DFV series units are classified as fan−assisted Category I furnaces when vertically vented according to the latest edition of National Fuel Gas Code (NFPA 54 / ANSI Z223.1). A fan−assisted Category I furnace is an appliance equipped with an integral mechanical means to either draw or force combustion products through the combustion chamber and/or heat exchanger.

NOTE − Use these instructions as a guide. They do not supersede local codes. This furnace must be vented according to all local codes, these installation instructions, and the provided venting tables in these instructions

The venting tables in this manual were extracted from the National Fuel Gas Code (NFPA 54 / ANSI Z223.1) and are provided as a guide for proper vent installation. Proper application, termination, construction and location of vents must conform to local codes having jurisdiction. In the absence of local codes, the NFGC serves as the defining document.

Refer to the tables and the venting information contained in these instructions to properly size and install the venting system.

IMPORTANT

Once the venting system is installed, attach the Disconnected Vent" warning sticker to a visible area of the plenum near the vent pipe. The warning sticker is provided in the bag assembly. Order kit 66W04 for additional stickers.

WARNING

Asphyxiation hazard. The exhaust vent for this furnace must be securely connected to the furnace flue transition at all times.

VENT CONNECTION

FLUE TRANSITION

COLLAR

FIGURE 14

Use self−drilling sheet metal screws or a mechanical fastener to firmly secure the vent pipe to the round collar of the flue transition. If self−drilling screws are used to attach the vent pipe, it is recommended that three be used. Drive one self−drilling screw through the front and one through each side of the vent pipe and collar. See figure 14.

Masonry chimneys used to vent Category I central furnaces must be either tile-lined or lined with a listed metal lining system or dedicated gas vent. Unlined masonry chimneys are prohibited. See figures 15 and 16 for common venting.

“DISCONNECTED VENT”

WARNING

STICKER

Page 12

Common Venting Using Tile−Lined Interior Masonry Chimney and Combined Vent Connector

MINIMUM LENGTH = AS SHORT AS PRACTICAL.

NOTE− Refer to provided venting

tables for installations.

FOR MAXIMUM LENGTH SEE NOTE TO LEFT

OTHER

APPLIANCE

FIGURE 15 Venting Using a Masonry Chimney

The following additional requirements apply when a lined masonry chimney is used to vent this furnace.

A chimney with one or more sides exposed to the outside of the structure is considered to be an exterior chimney.

An exterior masonry chimney that is not tile−lined must be lined with B1 vent or a listed insulated flexible metal vent. An exterior tile−lined chimney that is sealed and capped may be lined with a listed uninsulated flexible metal vent.

If the existing chimney will not accommodate a listed metal liner, either the chimney must be rebuilt to accommodate one of these liners or an alternate approved venting method must be found.

Insulation for the flexible vent pipe must be an encapsulated fiberglass sleeve recommended by the flexible vent pipe manufacturer. See figure 16.

Common Venting Using Metal−Lined Masonry Chimney

SEALED

MAX. LENGTH

−− SEE NOTE

5 ft. (1.5 m)

minimum

VENT CONNECTOR

4 in. (102 mm)

minimum

OTHER

APPLIANCE

NOTE 1 − Refer to the provided venting tables for installations.

BELOW.

MIN. LENGTH −− AS

SHORT AS PRACTICAL

FURNACE

EXTERIOR

CHIMNEY WITH

METAL

LINER

PERMANENTLY

SEALED FIREPLACE

OPENING

FIGURE 16

INTERIOR TILE−LINED MASONRY CHIMNEY

NOTE − the chimney must be properly sized per provided venting tables or lined with listed metal lining system.

VENT

CONNECTOR

FURNACE

PERMANENTLY SEALED FIREPLACE OPENING

DO NOT insulate the space between the liner and the chimney wall with puffed mica or any other loose granular insulating material

IMPORTANT

SINGLE appliance venting of a fan-assisted furnace into a tile-lined masonry chimney (interior or outside wall) is PROHIBITED. The chimney must first be lined with either type B1 vent or an insulated single wall flexible vent lining system which has been sized according to the provided venting tables and the vent pipe manufacturer’s instructions.

A fan−assisted furnace may be commonly vented into an existing lined masonry chimney if the following conditions are met:

 The chimney is currently serving at least one drafthood

equipped appliance

 The vent connectors and chimney are sized according

to the provided venting tables.

If type B1 double-wall vent is used inside a chimney, no other appliance can be vented into the chimney. The outer wall of type B1 vent pipe must not be exposed to flue products.

A type B1 vent or masonry chimney liner shall terminate above the roof surface with a listed cap or a listed roof assembly according to the terms of their respective listings and the vent manufacturer’s instructions.

When inspection reveals that an existing chimney is not safe for the intended purpose, it shall be rebuilt to conform to nationally recognized standards, lined or relined with suitable materials, or replaced with a gas vent or chimney suitable for venting SL280DFV series units. The chimney passageway must be checked periodically to ensure that it is clear and free of obstructions.

Do not install a manual damper, barometric draft regulator, or flue restrictor between the furnace and the chimney.

Page 13

Never connect a Category I appliance to a chimney that is servicing a solid−fuel appliance. If a fireplace chimney flue is used to vent this appliance, the fireplace opening must be permanently sealed.

A type B or listed chimney lining system that passes through an unused masonry chimney flue is not considered to be exposed to the outdoors.

General Venting Requirements

Vent all SL280DFV furnaces according to these instructions:

1 − Vent diameter recommendations and maximum allow-

able piping runs are found in the provided venting tables.

2 − In no case should the vent or vent connector diameter

be less than the diameter specified in the provided venting tables.

3 − The minimum vent capacity determined by the sizing

tables must be less than the low fire input rating and the maximum vent capacity must be greater than the high fire input rating.

4 − Single appliance vents − If the vertical vent or tile-lined

chimney has a larger diameter or flow area than the vent connector, use the vertical vent diameter to determine the minimum vent capacity and the vent

connector diameter to determine the maximum vent capacity. The flow area of the vertical vent, however,

shall not exceed 7 times the flow area of the listed appliance categorized vent area, drafthood outlet area or flue collar area unless designed according to approved engineering methods.

5 − Multiple appliance vents − The flow area of the largest

section of vertical vent or chimney shall not exceed 7 times the smallest listed appliance categorized vent area, drafthood outlet area or flue collar area unless designed according to approved engineering methods.

6 − The entire length of single wall metal vent connector

shall be readily accessible for inspection, cleaning, and replacement.

7 − Single appliance venting configurations with zero lat-

eral lengths (tables 5 and 6) are assumed to have no elbows in the vent system. For all other vent configurations, the vent system is assumed to have two 90° elbows. For each additional 90° elbow or equivalent (for example two 45° elbows equal one 90° elbow) beyond two, the maximum capacity listed in the venting table should be reduced by 10% (0.90 x maximum listed capacity).

8 − The common venting tables (7, 8, 9, and 10) were gen-

erated using a maximum horizontal vent connector length of 1−1/2 feet (.46 m) for each inch (25 mm) of connector diameter as follows:

TABLE 4

Connector Diameter

inches (mm)

3 (76) 4−1/2 (1.37)

4 (102) 6 (1.83)

5 (127) 7−1/2 (2.29)

6 (152) 9 (2.74)

7 (178) 10−1/2 (3.20)

Maximum Horizontal

Connector Length feet (m)

9 − If the common vertical vent is offset, the maximum

common vent capacity listed in the common venting tables should be reduced by 20%, the equivalent of two 90° elbows (0.80 x maximum common vent capacity). The horizontal length of the offset shall not exceed 1-1/2 feet (.46 m) for each inch (25 mm) of common vent diameter.

10 − The vent pipe should be as short as possible with the

least number of elbows and angles required to complete the job. Route the vent connector to the vent using the shortest possible route.

11 − A vent connector shall be supported without any dips

or sags and shall slope a minimum of 1/4 inch (6.4 mm) per linear foot (305 mm) of connector, back toward the appliance.

12 − Vent connectors shall be firmly attached to the furnace

flue collar by self−drilling screws or other approved means, except vent connectors of listed type B vent material which shall be assembled according to the manufacturer’s instructions. Joints between sections of single wall connector piping shall be fastened by screws or other approved means.

13 − When the vent connector used for Category I ap-

pliances must be located in or pass through a crawlspace or other areas which may be cold, that portion of the vent connector shall be constructed of listed double-wall type B vent material or material having equivalent insulation qualities.

14 − All venting pipe passing through floors, walls, and ceil-

ings must be installed with the listed clearance to combustible materials and be fire stopped according to local codes. In absence of local codes, refer to NFGC (Z223.1).

15 − No portion of the venting system can extend into, or pass

through any circulation air duct or plenum.

16 − Vent connectors serving Category I appliances shall

not be connected to any portion of mechanical draft systems operating under positive pressure such as Category III or IV venting systems.

17 − If vent connectors are combined prior to entering the

common vent, the maximum common vent capacity listed in the common venting tables must be reduced by 10%, the equivalent of one 90° elbow (0.90 x maximum common vent capacity).

Page 14

18 − The common vent diameter must always be at least as

large as the largest vent connector diameter.

19 − In no case, shall the vent connector be sized more than

two consecutive table size diameters over the size of the draft hood outlet or flue collar outlet.

20 − Do not install a manual damper, barometric draft regu-

lator or flue restrictor between the furnace and the

21 − When connecting this appliance to an existing dedi-

cated or common venting system, you must inspect the venting system’s general condition and look for signs of corrosion. The existing vent pipe size must conform to these instructions and the provided venting tables. If the existing venting system does not meet these requirements, it must be resized.

chimney.

TABLE 5

Capacity of Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving a Single Category I Appliance

Vent and Connector Diameter − D (inches)

Height

(feet)

NOTE − Single appliance venting configurations with zero lateral lengths are assumed to have no elbows in the vent system. For all other vent configurations, the vent system is assumed to have two 90° elbows. For each additional 90° elbow or equivalent (for example two 45° elbows equal one 90° elbow) beyond two, the maximum capacity listed in the venting table should be reduced by 10 percent (0.90 x maximum listed capacity).

Lateral

(feet)

0 0 78 0 152 0 251 0 375

2 13 51 18 97 27 157 32 232

4 21 49 30 94 39 153 50 227

6 25 46 36 91 47 149 59 223

0 0 84 0 165 0 276 0 415

2 12 57 16 109 25 178 28 263

5 23 53 32 103 42 171 53 255

8 28 49 39 98 51 164 64 247

0 0 88 0 175 0 295 0 447

2 12 61 17 118 23 194 26 289

5 23 57 32 113 41 187 52 280

10 30 51 41 104 54 176 67 267

0 0 94 0 191 0 327 0 502

2 11 69 15 136 20 226 22 339

5 22 65 30 130 39 219 49 330

10 29 59 40 121 51 206 64 315

15 35 53 48 112 61 195 76 301

0 0 97 0 202 0 349 0 540

2 10 75 14 149 18 250 20 377

5 21 71 29 143 38 242 47 367

10 28 64 38 133 50 229 62 351

15 34 58 46 124 59 217 73 337

20 48 52 55 116 69 206 84 322

0 0 100 0 213 0 374 0 587

2 9 81 13 166 14 283 18 432

5 21 77 28 160 36 275 45 421

10 27 70 37 150 48 262 59 405

15 33 64 44 141 57 249 70 389

20 56 58 53 132 66 237 80 374

30 NR NR 73 113 88 214 104 346

3 Inch 4 Inch 5 Inch 6 Inch

Appliance Input Rating in Thousands of Btu Per Hour

MIN MAX MIN MAX MIN MAX MIN MAX

Page 15

TABLE 6

Capacity of Type B Double−Wall Vents with Single−Wall Metal Connectors

Serving a Single Category I Appliance

Vent and Connector Diameter − D (inches)

Height

(feet)

Lateral

(feet)

0 38 77 59 151 85 249 126 373

2 39 51 60 96 85 156 123 231

4 NR NR 74 92 102 152 146 225

6 NR NR 83 89 114 147 163 220

0 37 83 58 164 83 273 123 412

2 39 56 59 108 83 176 121 261

5 NR NR 77 102 107 168 151 252

8 NR NR 90 95 122 161 175 243

0 37 87 57 174 82 293 120 444

2 39 61 59 117 82 193 119 287

5 52 56 76 111 105 185 148 277

10 NR NR 97 100 132 171 188 261

0 36 93 56 190 80 325 116 499

2 38 69 57 136 80 225 115 337

5 51 63 75 128 102 216 144 326

10 NR NR 95 116 128 201 182 308

15 NR NR NR NR 158 186 220 290

0 35 96 54 200 78 346 114 537

2 37 74 56 148 78 248 113 375

5 50 68 73 140 100 239 141 363

10 NR NR 93 129 125 223 177 344

15 NR NR NR NR 155 208 216 325

20 NR NR NR NR 186 192 254 306

0 34 99 53 211 76 372 110 584

2 37 80 55 164 76 281 109 429

5 49 74 72 157 98 271 136 417

10 NR NR 91 144 122 255 171 397

15 NR NR 11 5 131 151 239 208 377

20 NR NR NR NR 181 223 246 357

30 NR NR NR NR NR NR NR NR

3 Inch 4 Inch 5 Inch 6 Inch

Appliance Input Rating in Thousands of Btu Per Hour

MIN MAX MIN MAX MIN MAX MIN MAX

Page 16

Vent

Height

(feet)

TABLE 7

Vent Connector Capacity

Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving Two or More Category I Appliances

Connector

Rise

(feet)

1 22 37 35 66 46 106 58 164

2 23 41 37 75 48 121 60 183

3 24 44 38 81 49 132 62 199

1 22 40 35 72 49 114 64 176

2 23 44 36 80 51 128 66 195

3 24 47 37 87 53 139 67 210

1 22 43 34 78 49 123 65 189

2 23 47 36 86 51 136 67 206

3 24 50 37 92 52 146 69 220

1 21 50 33 89 47 142 64 220

2 22 53 35 96 49 153 66 235

3 24 55 36 102 51 163 68 248

1 21 54 33 99 46 157 62 246

2 22 57 34 105 48 167 64 259

3 23 60 35 110 50 176 66 271

1 20 62 31 113 45 181 60 288

2 21 64 33 118 47 190 62 299

3 22 66 34 123 48 198 64 309

3 Inch 4 Inch 5 Inch 6 Inch

MIN MAX MIN MAX MIN MAX MIN MAX

Vent and Connector Diameter − D (inches)

Appliance Input Rating in Thousands of Btu Per Hour

TABLE 8

Common Vent Capacity

Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving Two or More Category I Appliances

Vent

Height

(feet)

6 92 81 140 11 6 204 161 309 248

8 101 90 155 129 224 178 339 275

10 110 97 169 141 243 194 367 299

15 125 112 195 164 283 228 427 352

20 136 123 215 183 314 255 475 394

30 152 138 244 210 361 297 547 459

FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT

4 Inch 5 Inch 6 Inch 7 Inch

Appliance Input Rating in Thousands of Btu Per Hour

Common Vent Diameter − D (inches)

Page 17

Height

(feet)

TABLE 9

Vent Connector Capacity

Type B Double−Wall Vents with Single−Wall Metal Connectors

Serving Two or More Category I Appliances

Vent and Connector Diameter − D (inches)

Lateral

(feet)

1 NR NR NR NR NR NR NR NR

2 NR NR NR NR NR NR 168 182

3 NR NR NR NR 121 131 175 198

1 NR NR NR NR NR NA NR NR

2 NR NR NR NR 125 126 184 193

3 NR NR NR NR 130 138 191 208

1 NR NR NR NR 119 121 182 186

2 NR NR 84 85 124 134 189 203

3 NR NR 89 91 129 144 197 217

1 NR NR 79 87 116 138 177 214

2 NR NR 83 94 121 150 185 230

3 NR NR 87 100 127 160 193 243

1 49 56 78 97 115 152 175 238

2 52 59 82 103 120 163 182 252

3 55 62 87 107 125 172 190 264

1 47 60 77 110 112 175 169 278

2 51 62 81 115 117 185 177 290

3 54 64 85 119 122 193 185 300

3 Inch 4 Inch 5 Inch 6 Inch

Appliance Input Rating in Thousands of Btu Per Hour

MIN MAX MIN MAX MIN MAX MIN MAX

TABLE 10

Common Vent Capacity

Type B Double−Wall Vents with Single−Wall Metal Connectors

Serving Two or More Category I Appliances

Vent

Height

(feet)

6 NA 78 NA 11 3 200 158 304 244

8 NA 87 NA 126 218 173 331 269

10 NA 94 163 137 237 189 357 292

15 121 108 189 159 275 221 416 343

20 131 118 208 177 305 247 463 383

30 145 132 236 202 350 286 533 446

FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT

4 Inch 5 Inch 6 Inch 7 Inch

Appliance Input Rating in Thousands of Btu Per Hour

Common Vent Diameter − D (inches)

Page 18

Removal of the Furnace from Common Vent

In the event that an existing furnace is removed from a venting system commonly run with separate gas appliances, the venting system is likely to be too large to properly vent the remaining attached appliances.

Conduct the following test while each appliance is operating and the other appliances (which are not operating) remain connected to the common venting system. If the venting system has been installed improperly, you must correct the system as indicated in the general venting requirements section.

7 − If a venting problem is found during any of the preced-

ing tests, the common venting system must be modified to correct the problem.

Resize the common venting system to the minimum vent pipe size determined by using the appropriate tables in Appendix G. (These are in the current standards of the National Fuel Gas Code ANSI Z223.1.

Gas Piping

WARNING

CARBON MONOXIDE POISONING HAZARD Failure to follow the steps outlined below for each

appliance connected to the venting system being placed into operation could result in carbon monoxide poisoning or death. The following steps shall be followed for each appliance connected to the venting system being placed into operation, while all other appliances connected to the venting system are not in operation:

1 − Seal any unused openings in the common venting sys-

tem.

2 − Inspect the venting system for proper size and horizontal

pitch. Determine that there is no blockage, restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.

3 − Close all building doors and windows and all doors be-

tween the space in which the appliances remaining connected to the common venting system are located and other spaces of the building. Turn on clothes dryers and any appliances not connected to the common venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed. Do not operate a summer exhaust fan. Close fireplace dampers.

4 − Follow the lighting instructions. Turn on the appliance

that is being inspected. Adjust the thermostat so that the appliance operates continuously.

5 − After the main burner has operated for 5 minutes, test

for leaks of flue gases at the draft hood relief opening. Use the flame of a match or candle, or smoke from a cigarette, cigar, or pipe.

6 − After determining that each appliance connected to the

common venting system is venting properly, (step 3) return all doors, widows, exhaust fans, fireplace dampers, and any other gas−burning appliances to their previous mode of operation.

CAUTION

If a flexible gas connector is required or allowed by the authority that has jurisdiction, black iron pipe shall be installed at the gas valve and extend outside the furnace cabinet. The flexible connector can then be added between the black iron pipe and the gas supply line.

Gas Supply

1 − This unit is shipped standard for left or right side instal-

lation of gas piping. Connect the gas supply to the piping assembly.

2 − When connecting the gas supply piping, consider fac-

tors such as length of run, number of fittings, and furnace rating to avoid excessive pressure drop. Table 11 lists recommended pipe sizes for typical applications.

3 − The gas piping must not run in or through air ducts,

clothes chutes, gas vents or chimneys, dumb waiters, or elevator shafts.

4 − The piping should be sloped 1/4 inch (6.4 mm) per 15

feet (4.57 m) upward toward the meter from the furnace. The piping must be supported at proper intervals [every 8 to 10 feet (2.44 to 3.01 m)] with suitable hangers or straps. Install a drip leg inside vertical pipe runs to the unit.

5 − A 1/8" N.P.T. plugged tap or pressure post is located

on the gas valve to facilitate test gauge connection. See figures 26 and 27.

6 − In some localities, codes may require the installation of

a manual main shut-off valve and union (furnished by the installer) external to the unit. The union must be of the ground joint type.

IMPORTANT

Compounds used on threaded joints of gas piping must be resistant to the actions of liquified petroleum gases.

Page 19

TABLE 11

Gas Pipe Capacity − ft

Nominal

Iron Pipe

Size

inches

(mm)

1/2

(12.7)

3/4

(19.05)

(25.4)

1−1/4

(31.75)

1−1/2

(38.1)

(50.8)

2−1/2

(63.5)

(76.2)

NOTE − Capacity given in cubic feet (m3 ) of gas per hour and based on 0.60 specific gravity gas.

Internal

Diameter

inches

(mm)

.622

(17.799)

.824

(20.930)

1.049

(26.645)

1.380

(35.052)

1.610

(40.894)

2.067

(52.502)

2.469

(67.713)

3.068

(77.927)

(3.048)20(6.096)30(9.144)40(12.192)50(15.240)60(18.288)70(21.336)80(24.384)90(27.432)

175

(4.96)

360

(10.19)

680

(919.25)

1400

(39.64)

2100

(59.46)

3950

(111.85)

6300

(178.39)

11000

(311.48)

120

(3.40)

250

(7.08)

465

(13.17)

950

(26.90)

460

(41.34)

2750

(77.87)

4350

(123.17)

7700

(218.03)

(2.75)

200

(5.66)

375

(10.62)

770

(21.80)

1180

(33.41)

2200

(62.30)

3520

(99.67)

6250

(176.98)

(2.32)

170

(4.81)

320

(9.06)

660

(18.69)

990

(28.03)

1900

(53.80)

3000

(84.95

5300

(150.07)

/hr (m3/hr)

Length of Pipe − feet (m)

(2.07)

151

(4.28)

285

(8.07)

580

(16.42)

900

(25.48)

1680

(47.57)

2650

(75.04)

4750

(134.50)

(1.87)

138

(3.91)

260

(7.36)

530

(15.01)

810

(22.94)

1520

(43.04)

2400

(67.96)

4300

(121.76)

(1.73)

125

(3.54)

240

(6.80)

490

(13.87)

750

(21.24)

1400

(39.64)

2250

(63.71)

3900

(110.43)

(1.61)

118

(3.34)

220

(6.23)

460

(13.03)

690

(19.54)

1300

(36.81)

2050

(58.05)

3700

(104.77)

(1.50)

110

(3.11)

205

(5.80)

430

(12.18)

650

(18.41)

1220

(34.55)

1950

(55.22)

3450

(97.69)

100

(30.480)

(1.42)

103

(2.92)

195

(5.52)

400

(11.33)

620

(17.56)

1150

(32.56)

1850

(52.38)

3250

(92.03)

MANUAL

MAIN SHUT−OFF

VALV E

GROUND

JOINT

UNION

Left Side Piping

(Standard)

DRIP LEG

AUTOMATIC

GAS VALVE

AUTOMATIC

GAS VALVE

(with manual

shut−off valve)

FIELD

PROVIDED

AND INSTALLED

NOTE − BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET

(with manual

shut−off valve)

FIGURE 17

MANUAL

MAIN SHUT−OFF

VALV E

GROUND

JOINT

UNION

DRIP LEG

Right Side Piping

(Alternate)

Page 20

Leak Check

After gas piping is completed, carefully check all piping connections (factory− and field−installed) for gas leaks. Use a leak detecting solution or other preferred means.

NOTE − If emergency shutoff is necessary, shut off the main manual gas valve and disconnect the main power to the furnace. The installer should properly label these devices.

CAUTION

Some soaps used for leak detection are corrosive to certain metals. Carefully rinse piping thoroughly after leak test has been completed. Do not use matches, candles, flame or other sources of ignition to check for gas leaks.

Refer to figure 24 for unit field wiring. See figures 21 and 22 for icomfort Touch

thermostat wiring in communicating applications. Table 13 shows DIP switch and on−board link settings for non−communicating thermostat applications. Typical wiring schematic is shown in figure 23.

INTERIOR MAKE−UP BOX INSTALLATION

(Left Side)

The furnace must be isolated from the gas supply system by closing its individual manual shut-off valve during any pressure testing of the gas supply system at pressures less than or equal to 1/2 psig (3.48 kPa, 14 inches w.c.).

IMPORTANT

When testing pressure of gas lines, gas valve must be disconnected and isolated. See figure 18. Gas valves can be damaged if subjected to pressures greater than 1/2 psig (3.48 kPa, 14 inches w.c.).

MANUAL MAIN

SHUT−OFF VALVE

WILL NOT HOLD

NORMAL TEST

PRESSURE

1/8 NPT PLUG

CAP

FIGURE 18

Electrical

ELECTROSTATIC DISCHARGE (ESD)

Precautions and Procedures

ISOLATE

GAS VALVE

FURNACE

MAKE−UP

BOX

FIGURE 19

INTERIOR MAKE−UP BOX INSTALLATION

(Right Side)

MAKE−UP

BOX

Cut the two wire ties to extend power wires for right side only

FIGURE 20

CAUTION

Electrostatic discharge can affect electronic components. Take precautions to neutralize electrostatic charge by touching your hand and tools to metal prior to handling the control.

The unit is equipped with a field make−up box on the left hand side of the cabinet. The make−up box may be moved to the right side of the furnace to facilitate installation. If the make−up box is moved to the right hand side, clip the wire ties that bundle the wires together. Secure the excess wire to the existing harness to protect it from damage.

1 − The power supply wiring must meet Class I restric-

tions. Protected by either a fuse or circuit breaker, select circuit protection and wire size according to unit nameplate.

NOTE − Unit nameplate states maximum current draw. Maximum over−current protection allowed is shown in table

12.

TABLE 12

SL280DF Model

070V36A 15

090V48B, 090V60C, 110V60C 20

Maximum Over−Current

Protection (Amps)

Page 21

2 − Holes are on both sides of the furnace cabinet to facili-

tate wiring.

3 − Install a separate (properly sized) disconnect switch

near the furnace so that power can be turned off for servicing.

4 − Before connecting the thermostat or the power wiring,

check to make sure the wires will be long enough for servicing at a later date. Remove the blower access panel to check the length of the wire.

5 − Complete the wiring connections to the equipment.

Use the provided unit wiring diagram and the field wiring diagrams shown in table 13 and figure 24. Use 18−gauge wire or larger that is suitable for Class II rating for thermostat connections.

6 − Electrically ground the unit according to local codes or,

in the absence of local codes, according to the current National Electric Code (ANSI/NFPA No. 70). A green ground wire is provided in the field make−up box.

NOTE − The SL280DFV furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.

7 − One line voltage ACC" 1/4" spade terminal is provided

on the furnace integrated control. Any electronic air cleaner or other accessory rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to the one of the provided neutral terminals. See figure 25 for control configuration. This terminal is energized when the indoor blower is operating.

8 − An unpowered, normally open (dry) set of contacts with

a 1/4" spade terminal HUM" are provided for humidifier connections and may be connected to 24V or 120V. Any humidifier rated up to one amp can be connected to these terminals. In 120V humidifier applications the neutral leg of the circuit can be connected to one of the provided neutral terminals. This terminal is energized in the heating mode.

9 − Install the room thermostat according to the instruc-

tions provided with the thermostat. See table 13 for field wiring connections in varying applications. If the furnace is being matched with a heat pump, refer to the instruction packaged with the dual fuel thermostat.

Thermostat Selection

CAUTION

Field wiring for both communicating and non−communicating applications is illustrated in diagrams, which begin on Page 23.

Non−Communicating

In non−communicating applications the SL280DFV is designed to operate in a SINGLE−STAGE mode or TWO− STAGE mode using a conventional thermostat.

For optimal performance in non−communicating applications, Lennox recommends use of a ComfortSense high quality electronic digital thermostat or any other with adjustable settings for 1st stage / 2nd stage on / off differentials and adjustable stage timers.

Lennox recommends the following two−stage thermostat settings: First heat stage differential set to 1/2 to 1 degree F; second heat stage differential set to 1/2 or 1 degree F; second heat stage upstage timer disabled, or set to maximum (1 hr minimum).

Communicating

In communicating applications the icomfort Touch® thermostat must be used. Refer to the instructions provided with the thermostat for installation, set−up and operation. In communicating system all unused thermostat wire in the wire bundle needs to be terminated inside and out. The extra wires can terminate on the ’C" terminal of the icomfort communication terminal strip. (RSBus). Using an additional wire come off "C" terminal and wire nut all the extra wires together. Termination on the outdoor control must match the indoor control.

Indoor Blower Speeds

Non−Communicating

1 − When the thermostat is set to FAN ON," the indoor

blower will run continuously at a field selectable percentage of the second−stage cooling speed when there is no cooling or heating demand. The factory default setting is 38% of cool speed.

2 − When the SL280DFV is running in the heating mode,

the indoor blower will run on the heating speed designated by the positions of DIP switches 11, 12 and 13. First stage heating will run at 91% heat speed.

3 − When there is a cooling demand, the indoor blower will

run on the cooling speed designated by the positions of DIP switches 5 and 6. First stage cooling will run at 70% cool speed.

Communicating

NOTE − When the SL280DFV is used with icomfort

Touch tions are made by the communicating thermostat.

1 − When the thermostat is set to FAN ON," the indoor

blower will run at setting determined during system configuration.

2 − When there is a heating demand the fan will run on

heating speeds for firing rate.

3 − When there is a cooling demand, the fan will run on the

first stage and second stage cooling speed set using the icomfort Touch® thermostat in the installer setup mode. The factory default is based upon 400 CFM a ton.

thermostat, proper indoor blower speed selec-

7000

Page 22

Generator Use − Voltage Requirements

The following requirements must be kept in mind when specifying a generator for use with this equipment:

 The furnace requires 120 volts (Range: 102 volts to

132 volts)

 The furnace operates at 60 Hz +

5% (Range: 57 Hz to

63 Hz)

icomfort Touch

Thermostat with SL280DFV

and Non−Communicating Outdoor Unit

 The furnace integrated control requires both correct

polarity and proper ground. Both polarity and proper grounding should be checked before attempting to operate the furnace on either permanent or temporary power

 Generator should have a wave form distortion of less

than 5% THD (total harmonic distortion)

icomfort Touch® Thermostat with SL280DFV

and icomfort−ENABLED Outdoor Unit

icomfort Touch® Thermostat icomfort−Enabled SL280DFV Indoor Furnace Non−Communicating Outdoor Air Conditioner

icomfort− ENABLED

SL280DFV

OPTIONAL

DISCHARGE

AIR SENSOR

icomfort Touch®

THERMOSTAT

CLIP ON−BOARD LINK

W915 (Y1 TO Y2) FOR

TWO−STAGE OPERATION

FURNACE

OPTIONAL OUTDOOR

AIR SENSOR

NON−COMMUNICATING

OUTDOOR AIR

CONDITIONING UNIT −

1 OR 2 STAGE

icomfort Touch® Thermostat icomfort−Enabled SL280DFV Indoor Furnace icomfort−Enabled Outdoor Air Conditioner or Heat Pump

icomfort−

ENABLED SL280DFV FURNACE

OPTIONAL

DISCHARGE

AIR SENSOR

OPTIONAL OUTDOOR

AIR SENSOR

icomfort Touch®

THERMOSTAT

icomfort− ENABLED

OUTDOOR AIR CONDITIONING

OR HEAT PUMP UNIT

Outdoor Unit

NOTE − On communicating systems, extra wires must terminate on the "C" RSBus terminal. Use an additional wire and come off "C" terminal and wire nut all the extra wires together. Termination on the outdoor control must match the indoor control.

icomfort Integrated Control

icomfort Touch

FIGURE 21

Page 23

Optional Accessories for use with any icomfort Touch® System

NOTE: icomfort Touch® THERMOSTAT SENSES HUMIDITY & CONTROLS HUM CONTACTS TO CYCLE HUMIDIFIER BASED ON DEMAND. NO OTHER CONTROL OR HUMIDISTAT REQUIRED.

OPTIONAL OUTDOOR AIR SENSOR FOR USE WITH HUMIDIFIER (IF NOT ALREADY IN THE SYSTEM FOR OTHER FUNCTIONS. BUILT INTO ALL icomfort by Lennox OUT- DOOR UNITS).

120V CONNECTIONS

HUM" CONTACT IS CLOSED ANYTIME HUMIDITY DEMAND IS PRESENT

Discharge Air

Sensor (Required

for even heat)

icomfort Touch

THERMOSTAT

RSBus

Maximum total length of all connections on the RSBus is limited to 1500ft.

Wire gauge of RSBus wire is 18.

icomfort ENABLED SL280DFV FURNACE

ENABLED OUTDOOR

AIR CONDITIONING OR

HEAT PUMP UNIT

icomfort 

NOTE: 24V UV LIGHT APPLICATIONS

In an icomfort by Lennox system, neither furnace nor air handler former will have adequate VA to power 24V UV light applications. An additional transformer for UV light applications is required.

trans-

icomfort Touch

THERMOSTAT

DEHUMIDIFIER CONTROL

Rf WGhGsCf

HVAC EQUIP

24V HUMIDIFIER CONNECTIONS

CS 7000 THERMOSTAT

CONVENTIONAL NON−COMMUNICATING SYSTEM

COMMUNICATING SYSTEM

*24V IN jumper not used in non− communicating configuration

*24V IN JUMPER

icomfort ENABLED SL280DFV FURNACE

SL280DFV FURNACE

icomfort ENABLED

HEPA BYPASS FILTER X2680 HEPA INTERLOCK KIT

SL280DFV FURNACE

icomfort ENABLED

LVCS VENTILATION CONTROL SYSTEM

SL280DFV FURNACE

icomfort ENABLED

(POWER COMPANY INTERRUPTION SYSTEMS ARE WIRED SAME AS OVERFLOW SWITCH)

PASS INDOOR BLOWER MOTOR COMMON WIRE THROUGH CURRENT LOOP.

SEE HEPA INTERLOCK KIT FOR INSTALLATION DETAILS

SEE LVCS VENTILATION INSTRUCTIONS FOR DAMPER & SENSOR WIRING

FIGURE 22

Page 24

HVAC EQUIPMENT

STANDARD 1 OR 2

STAGE AC OR HP UNIT

2 STAGE FURNACE

CUT R−DS W914

NON−COMMUNICATING SYSTEM WIRING

COMMUNICATING SYSTEM WIRING

Thermostat

1 Heat / 1 Cool

NOTE − Use DIP switch 2 to set second−stage heat ON delay. OFF−7 minutes. ON−12 minutes.

TABLE 13

SL280 Field Wiring Applications With Conventional Thermostat

DIP Switch Settings and On−Board Links (See figure 25)

DIP Switch 1

Thermostat

Heating

On Board Links Must Be Cut To Select

System Options

Stages

DO NOT CUT ANY ON−BOARD LINKS

Wiring Connections

T’STAT

FURNACE

TERM. STRIP

OUTDOOR

UNIT

1 Heat / 2 Cool

NOTE − Use DIP switch 2 to set second−stage heat ON delay. OFF−7 minutes. ON−12 minutes.

1 Heat / 2 Cool with t’stat with humidity control

NOTE − Use DIP switch 2 to set second−stage heat ON delay. OFF−7 minutes. ON−12 minutes.

CUT ON−BOARD LINK

W915

2 STAGE

COMPR

CUT ON−BOARD LINK

W915

2 STAGE

COMPR

CUT ON−BOARD LINK

W914

DEHUM

HARMONY

T’STAT

FURNACE

TERM. STRIP

FURNACE

TERM. STRIP

OUTDOOR

UNIT

OUTDOOR

UNIT

* Not required on all units.

Page 25

SL280 Field Wiring Applications With Conventional Thermostat (Continued)

DIP Switch Settings and On−Board Links (See figure 25)

DIP Switch 1

Thermostat

Heating

Stages

2 Heat / 2 Cool OFF

TABLE 13

On Board Links Must Be Cut To Select

System Options

CUT ON−BOARD LINK

W915

2 STAGE

COMPR

Wiring Connections

T’STAT

FURNACE

TERM. STRIP

OUTDOOR

UNIT

2 Heat / 2 Cool with t’stat with humidity control

2 Heat / 1 Cool with t’stat with humidity control

OFF

CUT ON−BOARD LINK

W915

2 STAGE

COMPR

CUT ON−BOARD LINK

W914

DEHUM

HARMONY

CUT ON−BOARD LINK

W914

DEHUM

HARMONY

T’STAT

FURNACE

TERM. STRIP

FURNACE

TERM. STRIP

OUTDOOR

UNIT

OUTDOOR

UNIT

2 Heat / 1 Cool OFF

* Not required on all units.

DO NOT CUT ANY ON−BOARD LINKS

Page 26

T’STAT

FURNACE

TERM. STRIP

OUTDOOR

UNIT

Thermostat

Dual Fuel Single Stage Heat Pump

ComfortSense 7000 L7724U thermostat w/ dual fuel capabilities Capable of 2 stage gas heat control

TABLE 13

SL280 Field Wiring Applications With Conventional Thermostat (Continued)

DIP Switch Settings and On−Board Links (figure 25)

DIP Switch 1

Thermostat

Heating

On Board Links Must Be Cut To Select

System Options

Wiring Connections

Stages

FURNACE

TERM. STRIP

OFF

CUT ON−BOARD LINK

W951 HEAT

PUMP

L7724U T’STAT

HEAT PUMP

67M41*

Dual Fuel Two Stage Heat Pump

ComfortSense

OFF

CUT ON−BOARD LINK

W915

2 STAGE

COMPR

L7724U T’STAT

FURNACE

TERM. STRIP

HEAT PUMP

67M41*

7000 L7724U thermostat w/ dual fuel capabilities Capable of 2 stage gas heat

CUT ON−BOARD LINK

W951 HEAT

PUMP

control

outdoor sensor

* Connect W1 to W1 ONLY if using defrost tempering kit 67M41

NOTE − Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the SL280 integrated control.

outdoor

sensor

out blue

Page 27

Thermostat

Dual Fuel Single Stage Heat Pump

ComfortSense 7000 L7724U thermostat w/ dual fuel capabilities Capable of 2 stage gas heat control w/dehumidification control

TABLE 13

SL280 Field Wiring Applications With Conventional Thermostat (Continued)

DIP Switch Settings and On−Board Links (figure 25)

DIP Switch 1

Thermostat

Heating

On Board Links Must Be Cut To Select

System Options

Wiring Connections

Stages

FURNACE

TERM. STRIP

OFF

CUT ON−BOARD LINK

W951 HEAT PUMP

CUT ON−BOARD LINK

W914

DEHUM

HARMONY

L7724U T’STAT

HEAT PUMP

67M41*

Dual Fuel Two Stage Heat Pump

ComfortSense 7000 L7724U thermostat w/ dual fuel capabilities Capable of 2 stage gas heat control w/dehumidification

OFF

CUT ON−BOARD LINK

W915

2 STAGE

COMPR

CUT ON−BOARD LINK

W951 HEAT

PUMP

CUT ON−BOARD LINK

W914

DEHUM

HARMONY

L7724U T’STAT

FURNACE

TERM. STRIP HEAT PUMP

67M41*

outdoor sensor

* Connect W1 to W1 ONLY if using defrost tempering kit 67M41

NOTE − Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the SL280 integrated control.

outdoor

sensor

out blue

Page 28

SL280DFV Schematic Wiring Diagram

FIGURE 23

Page 29

TYPICAL SL280DFV FIELD WIRING DIAGRAM

FIELD INSTALLED CLASS II 24V

FIELD INSTALLED LINE VOLTAGE

FIGURE 24

Page 30

Integrated Control

7 SEGMENT LED

FLAME SENSE

DIAGNOSTIC

PUSH BUTTON

DIP SWITCHES

HUM

LINE 1

ACC

HS/ CAI

INDOOR

BLOWER

CONNECTOR

NEUTRAL

OUTDOOR AIR

SENSOR

TERMINALS

DISCHARGE AIR

SENSOR

TERMINALS

TB83

COMMUNICATING

OUTDOOR

EQUIPMENT

I + I −CRI + I −

TB84

COMMUNICATING

INDOOR

THERMOSTAT

RS−BUS LINK (TB82, future use)

I+ = DATA HIGH CONNECTION I − = DATA LOW CONNECTION

RS−BUS OUTDOOR (TB83)

R = 24VAC I + = DATA HIGH CONNECTION I − = DATA LOW CONNECTION C = 24VAXC COMMON

RS−BUS INDOOR (TB84)

R = 24VAC I + = DATA HIGH CONNECTION I − = DATA LOW CONNECTION C = 24VAXC COMMON

1/4" QUICK CONNECT TERMINALS

HUM = UNPOWERED NORMALLY OPEN (DRY) CONTACTS

XMFR = 120 VAC OUTPUT TO TRANSFORMER

LI = 120 VAC INPUT TO CONTROL

ACC = 120 VAC OUTPUT TO OPTIONAL ACCESSORY

NEUTRALS = 120 VAC NEUTRAL

W1 W2 GY2Y1

NON−COMMUNICATINGNG

24V TERMINALS

12 PIN LOW

VOLTAGE

CONNECTOR

W915 Y1 TO Y2

2 STAGE COMPR

W951 R TO O HEAT PUMP

W914 R TO DS

DEHUM OR

RDHLODS

HARMONY

THERMOSTAT CONNECTIONS (TB1)

DS = DEHUMIDIFICATION SIGNAL

W2 = HEAT DEMAND FROM 2ND STAGE T/STAT

W1 = HEAT DEMAND FROM 1ST STAGE T/STAT R = CLASS 2 VOLTAGE TO THERMOSTAT

G = MANUAL FAN FROM T’STAT

C = THERMOSTAT SIGNAL GROUND CONNECTED TO TRANSFORMER GRD (TR) & CHASIS GROUND (GRD)

Y1 = THERMOSTAT 1ST STAGE COOL SIGNAL

Y2 = THERMOSTAT 2ND STAGE COOL SIGNAL

O = THERMOSTAT SIGNAL TO HEAT PUMP

DH = DEHUMIDIFICATION OUTPUT COMMUNICATING

L = USE ONLY WITH A COMMUNICATING THERMOSTAT

AND A NON−COMMUNICATING OUTDOOR UNIT

REVERSING VALVE

THERMOSTAT ONLY

. . . . . . . . . . . . .

FIGURE 25

Page 31

Integrated Control DIP Switch Settings − Conventional Thermostat (non−communicating)

SL280DFV units are equipped with a two−stage, variable speed integrated control. This control manages ignition timing, heating mode fan off delays and indoor blower speeds based on selections made using the control dip switches and jumpers. The control includes an internal watchguard feature which automatically resets the ignition control when it has been locked out. After one hour of continuous thermostat demand for heat, the watchguard will break and remake thermostat demand to the furnace and automatically reset the control to relight the furnace.

Note: All icomfortt settings are set at the icomfort Touch thermostat. See icomfortt installation instruction. In icomfortt communication system all DIP switch and clippable link settings are ignored. For conventional thermostats proceed with DIP switch and clippable link settings as outlined in the following.

Heating Operation DIP Switch Settings Switch 1 −− Thermostat Selection −− This unit may be used

with either a single−stage or two−stage thermostat. The thermostat selection is made using a DIP switch which must be properly positioned for the particular application. The DIP switch is factory−positioned for use with a two− stage thermostat. If a single−stage thermostat is to be used, the DIP switch must be repositioned.

Select OFF" for two−stage heating operation con-

trolled by a two−stage heating thermostat (factory setting);

b − Select ON" for two−stage heating operation con-

trolled by a single−stage heating thermostat. This setting provides a timed delay before second−stage heat is initiated.

Switch 2 −− Second Stage Delay (Used with Single− Stage Thermostat Only) −− This switch is used to deter-

mine the second stage on delay when a single−stage thermostat is being used. The switch is factory−set in the OFF position, which provides a 7−minute delay before second− stage heat is initiated. If the switch is toggled to the ON position, it will provide a 12−minute delay before second− stage heat is initiated. This switch is only activated when the thermostat selector jumper is positioned for SINGLE− stage thermostat use.

Switches 3 and 4 −− Blower−Off Delay −− The blower−on delay of 30 seconds is not adjustable. The blower−off delay (time that the blower operates after the heating demand has been satisfied) can be adjusted by moving switches 3 and 4 on the integrated control. The unit is shipped from the factory with a blower−off delay of 90 seconds. The blower off delay affects comfort and is adjustable to satisfy individual applications. Adjust the blower off delay to achieve a

supply air temperature between 90° and 110°F at the exact moment that the blower is de−energized. Longer off delay settings provide lower supply air temperatures; shorter settings provide higher supply air temperatures.Table 14 provides the blower off timings that will result from different switch settings.

Blower Off Delay Switch Settings

Blower Off Delay

(Seconds)

60 On Off

90 (Factory) Off Off

120 Off On

Indoor Blower Operation DIP Switch Settings Switches 5 and 6 −− Cooling Mode Blower Speed −− The

unit is shipped from the factory with the dip switches positioned for high speed (4) indoor blower motor operation during the cooling mode. Table 15 provides the cooling mode blower speeds that will result from different switch settings. Switches 5 and 6 set the blower cfm for second− stage cool. The integrated control automatically ramps down to 70% of the second−stage cfm for first−stage cfm. Refer to tables for corresponding cfm values.

Switches 7 and 8 −− Cooling Blower Speed Adjustment

−− The unit is shipped from the factory with the dip switches

positioned for NORMAL (no) adjustment. The dip switches may be positioned to adjust the blower speed by +10% or

−10% to better suit the application. Table 16 below provides blower speed adjustments that will result from different switch settings. Refer to tables for corresponding cfm values.

Switches 9 and 10 −− Cooling Mode Blower Speed Ramping −− Blower speed ramping may be used to en-

hance dehumidification performance. The switches are factory set at option A which has the greatest effect on de− humidification performance. Table 17 provides the cooling mode blower speed ramping options that will result from different switch settings. The cooling mode blower speed ramping options are detailed on the next page.

180 On On

Cooling Mode Blower Speeds

Speed

Low On On

Medium Low Off On

Medium High On Off

High (Factory) Off Off

Cooling Blower Speed Adjustment

Adjustment

+10% (approx.) On Off

Factory Default Off Off

−10% (approx.) Off On

TABLE 14

Switch 3 Switch 4

TABLE 15

Switch 5 Switch 6

TABLE 16

Switch 7 Switch 8

Page 32

NOTE − The off portion of the selected ramp profile also applies during heat pump operation in dual fuel applications.

TABLE 17

Cooling Mode Blower Speed Ramping

Ramping Option

Switch 9 Switch 10

A (Factory) Off Off

B Off On C On Off D On On

Ramping Option A (Factory Selection)

 Motor runs at 50% for 30 seconds.  Motor then runs at 82% for approximately 7−1/2 minu-

tes.

 If demand has not been satisfied after 7−1/2 minutes,

motor runs at 100% until demand is satisfied.

 Once demand is met, motor runs at 50% for 30 sec-

onds then ramps down to stop.

OFF

1/2 MIN 50% CFM

7 1/2 MIN 82% CFM

COMPRESSOR DEMAND

100% CFM

1/2 MIN 50% CFM

OFF

Ramping Option B

 Motor runs at 82% for approximately 7−1/2 minutes. If

demand has not been satisfied after 7−1/2 minutes, motor runs at 100% until demand is satisfied.

 Once demand is met, motor ramps down to stop.

OFF

7 1/2 MIN

82%CFM

COMPRESSOR DEMAND

100% CFM

OFF

Ramping Option C

 Motor runs at 100% until demand is satisfied.

 Once demand is met, motor runs at 100% for 45 sec-

onds then ramps down to stop.

OFF

100% CFM

COMPRESSOR

DEMAND

100% CFM

45 SEC.

OFF

Ramping Option D

 Motor runs at 100% until demand is satisfied.

 Once demand is met, motor ramps down to stop.

100% CFM

COMPRESSOR

DEMAND

OFFOFF

Switches 11, 12 and 13 −− Heating Mode Blower Speed −−

The switches are factory set to the OFF position which provides normal heat speed. Refer to table 18 for switches 11, 12 and 13 that provided the corresponding increases or decrease to both high and low heat demand.

TABLE 18

Heating Mode Blower Speeds

Heat Speed

Switch

Switch12Switch

Increase 24% On On On

Increase 18% On On Off

Increase 12% On Off On

Increase 6% On Off Off

Factory Default Off Off Off

Decrease 6% Off Off On

Decrease 12% Off On Off

Decrease18% Off On On

Switches 14 and 15 −− Continuous Blower Speed −−

Table 19 provides continuous blower speed adjustments that will result from different switch settings.

TABLE 19

Continuous Blower Speed

Continuous

Blower Speed

Switch 14 Switch 15

28% of High Cool Speed Off On

38% of High Cool Speed

(Factory)

Off Off

70% of High Cool Speed On Off

100% of High Cool Speed On On

Page 33

On−Board Links

Note: In icomfortt systems with a conventional outdoor unit (non−communicating), the on−board clippable links must be set to properly configure the system

WARNING

Carefully review all configuration information provided. Failure to properly set DIP switches, jumpers and on−board links can result in improper operation!

On−Board Link W914 Dehum or Harmony (R to DS)

On−board link W914, is a clippable connection between terminals R and DS on the integrated control. W914 must be cut when the furnace is installed with either the Harmony III zone control or a thermostat which features humidity control. If the link is left intact the PMW signal from the Harmony III control will be blocked and also lead to control damage. Refer to table 20 for operation sequence in applications including SL280DFV, a thermostat which features humidity control and a single−speed outdoor unit. Table 21 gives the operation sequence in applications with a two−speed outdoor unit.

On−Board Link W951 Heat Pump (R to O)

On−board link W951 is a clippable connection between terminals R and O on the integrated control. W951 must be cut when the furnace is installed in applications which include a heat pump unit and a thermostat which features dual fuel use. If the link is left intact, terminal O" will remain energized eliminating the HEAT MODE in the heat pump.

On−Board Link W915 2 Stage Compr (Y1 to Y2)

On−board link W915 is a clippable connection between ter-

minals Y1 and Y2 on the integrated control. W915 must be cut if two−stage cooling will be used. If the Y1 to Y2 link is not cut the outdoor unit will operate in second−stage cooling only.

Diagnostic LED (Figure 25)

The seven−segment diagnostic LED displays operating status, target airflow, error codes and other information. The table beginning on Page 48 lists diagnostic LED codes.

Diagnostic Push Button (Figure 25)

The diagnostic push button is located adjacent to the seven−segment diagnostic LED. This button is used to enable the Error Code Recall E" mode and the Flame Signal F" mode. Press the button and hold it to cycle through a menu of options. Every five seconds a new menu item will be displayed. When the button is released, the displayed item will be selected. Once all items in the menu have been displayed, the menu resumes from the beginning until the button is released.

Error Code Recall Mode

Select "E" from the menu to access the most recent 10 error codes. Select c" from the Error Code Recall menu to clear all error codes. Button must be pressed a second time while c" is flashing to confirm command to delete codes. Press the button until a solid ≡" is displayed to exit the Error Code Recall mode.

Flame Signal Mode

Select "F" from the menu to access the flame signal mode. The integrated control will display the flame current on 7 segment LED in in micro amps (uA).

Flame signal mode is exited after the following:

 Power is reset  Pressing and holding push button until 3 horizontal

lines ≡" are displayed

 10 minutes of entering the flame sense mode.

Page 34

BLOWER DATA

SL280DF070V36A BLOWER PERFORMANCE (less lter) 0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

Heating Speed

DIP Switch

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

Settings

+24% 1065 1170

+18% 1010 1115 +12% 960 1055

+6% 910 1000

Factory Default 860 945

–6% 805 885

–12% 755 830 –18% 705 775

Cooling Speed

DIP Switch

Settings

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

Low Medium-Low Medium-High

+ 745 870 1025 1075 1100 1240 1425 1515

Factory Default 665 780 925 985 1015 1115 1305 1380

– 590 690 815 865 900 1025 1170 1250

Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch

Settings.

Factory default setting.

NOTES - The effect of static pressure is included in air volumes shown.

First stage HEAT is approximately 91% of the same second stage HEAT.

First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position. Continuous Fan Only speed is selectable at 28%, 38%, 70% and 100% of the selected second stage cooling speed - minimum 500 cfm. Lennox Harmony III™ Zone Control Applications - Minimum blower speed is 425 cfm.

HEATING

COOLING

High Low Medium-Low Medium-High2 High

SL280DF090V48B BLOWER PERFORMANCE (less lter) 0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

Heating Speed

DIP Switch

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

Settings

+24% 1360 1500

+18% 1285 1415 +12% 1220 1350

+6% 1135 1285

Factory Default 1075 1200

–6% 1030 1110

–12% 960 1050 –18% 890 975

COOLING

Cooling Speed

DIP Switch

Settings

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

Low Medium-Low Medium-High

High Low Medium-Low Medium-High2 High

+ 740 905 1040 1220 1085 1330 1545 1730

Factory Default 690 820 950 1110 990 1200 1400 1,595

– 610 745 855 1005 895 1075 1270 1460

Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch

Settings.

Factory default setting.

NOTES - The effect of static pressure is included in air volumes shown.

First stage HEAT is approximately 91% of the same second stage HEAT.

Page 35

BLOWER DATA

SL280DF090V60C BLOWER PERFORMANCE (less lter) 0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

Heating Speed

DIP Switch

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

Settings

+24% 1540 1695

+18% 1465 1615 +12% 1390 1530

+6% 1320 1450

Factory Default 1245 1365

–6% 1170 1285

–12% 1095 1205 –18% 1020 1120

Cooling Speed

DIP Switch

Settings

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

Low Medium-Low Medium-High

+ 1125 1250 1400 1590 1585 1770 2000 2275

Factory Default 1020 1135 1285 1445 1420 1610 1845 2,050

– 900 1005 1155 1280 1305 1395 1645 1875

Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch

Settings.

Factory default setting.

NOTES - The effect of static pressure is included in air volumes shown.

First stage HEAT is approximately 91% of the same second stage HEAT.

HEATING

COOLING

High Low Medium-Low Medium-High2 High

SL280DF110V60C BLOWER PERFORMANCE (less lter) 0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

Heating Speed

DIP Switch

First Stage Heating Speed - cfm Second Stage Heating Speed - cfm

Settings

+24% 1645 1810

+18% 1565 1720 +12% 1485 1635

+6% 1405 1545

Factory Default 1325 1460

–6% 1245 1370

–12% 1170 1285 –18% 1090 1195

COOLING

Cooling Speed

DIP Switch

Settings

First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm

Low Medium-Low Medium-High

High Low Medium-Low Medium-High2 High

+ 1075 1225 1370 1530 1500 1755 1915 2120

Factory Default 945 1120 1230 1385 1360 1585 1770 1960

– 880 985 1135 1235 1225 1405 1595 1760

Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch

Settings.

Factory default setting.

NOTES - The effect of static pressure is included in air volumes shown.

First stage HEAT is approximately 91% of the same second stage HEAT.

Page 36

TABLE 20

SL280DFV, Non−Communicating Thermostat with Humidity Control Feature and Single−Speed Outdoor Unit

OPERATING SEQUENCE

SYSTEM DEMAND SYSTEM RESPONSE

Thermostat Demand Relative Humidity

System

Condition

Step

Y1 O G

Status D

NO CALL FOR DEHUMIDIFICATION

Normal Operation 1 On On On Acceptable

VAC

BASIC MODE (only active on a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable

Dehumidification

Call

2 On On On Demand

VAC

PRECISION MODE (operates independent of a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable

Dehumidification

call

Dehumidification

call ONLY

2 On On On Demand

1 On On On Demand

VAC

Jumpers at indoor unit with a single stage outdoor unit With Condensing unit − Cut W914 (R to DS) on SureLight With Heat Pump − Cut W914 (R to DS) & W951 (R to O) on SureLight

ComfortSense

7000 thermostat to use for this application − Y2081 4 heat / 2 cool

*Dehumidification blower speed is 70% of COOL speed for all units . **In Precision mode, ComfortSense

7000 thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room

setting.

Compressor

High 100%

High 70%*

High 100%

High 70%*

board

Blower

CFM

(COOL)

board

Comments

Compressor and indoor blower follow thermostat demand

ComfortSense

7000 thermostat energizes Y1 and de−energizes D on a call for de−humidification

Dehumidification mode begins when humidity is greater than set point

ComfortSense

7000 thermostat will try to maintain room humidity setpoint by allowing the room space to maintain a cooler room thermostat setpoint**

Page 37

TABLE 21

SL280DFV, Non−Communicating Thermostat with Humidity Control Feature and Two−Speed Outdoor Unit

OPERATING SEQUENCE

SYSTEM DEMAND SYSTEM RESPONSE

Thermostat Demand Relative Humidity

System

Condition

Step

Y1 Y2 O G

W1W

Status D

NO CALL FOR DEHUMIDIFICATION

Normal Operation −

1 On On On Acceptable

2 On On On On Acceptable

VAC

ROOM THERMOSTAT CALLS FOR FIRST STAGE COOLING

BASIC MODE (only active on a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable

Dehumidification

Call

2 On On On On Demand

VAC

PRECISION MODE (operates independent of a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable

Dehumidification

call

Dehumidification

call ONLY

2 On On On On Demand

1 On On On On Demand

VAC

ROOM THERMOSTAT CALLS FOR FIRST AND SECOND STAGE COOLING

BASIC MODE (only active on a Y1 thermostat demand)

Normal Operation 1 On On On On Acceptable

Dehumidification

Call

2 On On On On Demand

VAC

PRECISION MODE (operates independent of a Y1 thermostat demand)

Normal Operation 1 On On On Acceptable

Dehumidification

call

Dehumidification

call ONLY

2 On On On On Demand

1 On On On On Demand

VAC

Jumpers at indoor unit with a two stage outdoor unit Cut factory jumper from Y1 to Y2 or cut W915 (Y1 to Y2) With Condensing unit − Cut W914 (R to DS) on SureLight With Heat Pump − Cut W914 (R to DS) & W951 (R to O) on SureLight

board

Compressor

Low 70%*

High 100%

Low 70%*

High 70%**

Low 70%*

High 70%**

High 100%

High 70%**

Low 70%*

High 70%**

control

Blower

CFM

(COOL)

Comments

Compressor and indoor blower follow thermostat demand

ComfortSense

7000 thermostat energizes Y2 and de−energizes D on a call for de−humidification

Dehumidification mode begins when humidity is greater than set point

ComfortSense® 7000 thermostat will try to maintain room humidity setpoint by allowing the room space to maintain a cooler room thermostat setpoint***

ComfortSense

7000 thermostat energizes Y2 and de−energizes D on a call for de−humidification

Dehumidification mode begins when humidity is greater than set point

ComfortSense

7000 thermostat will try to maintain room humidity setpoint by allowing the room space to maintain a cooler room thermostat setpoint***

ComfortSense® 7000 thermostat to use for this application − Y2081 4 heat / 2 cool *Normal operation first stage cooling blower speed is 70% COOL speed. **Dehumidification blower speed is, reduced to 70% of COOL. ***In Precision mode, ComfortSense

7000 thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room

setting.

Page 38

Unit Start−Up

FOR YOUR SAFETY READ BEFORE LIGHTING

WARNING

Do not use this furnace if any part has been underwater. Immediately call a licensed professional service technician (or equivalent) to inspect the furnace and to replace any part of the control system and any gas control which has been under water.

WARNING

If overheating occurs or if gas supply fails to shut off, shut off the manual gas valve to the appliance before shutting off electrical supply.

CAUTION

Before attempting to perform any service or maintenance, turn the electrical power to unit OFF at disconnect switch.

Gas Valve Operation (Figures 26 and 27)

1 − STOP! Read the safety information at the beginning of

this section. 2 − Set the thermostat to the lowest setting. 3 − Turn off all electrical power to the unit.

4 − This furnace is equipped with an ignition device which

automatically lights the burners. Do not try to light the

burners by hand. 5 − Remove the access panel. 6 − Move switch on gas valve to OFF. Do not force . See

figure 26 or 27. 7 − Wait five minutes to clear out any gas. If you then smell

gas, STOP! Immediately call your gas supplier from a

neighbor’s phone. Follow the gas supplier’s instruc-

tions. If you do not smell gas go to next step.

WHITE RODGERS GAS VALVE

INLET PRESSURE POST

MANIFOLD

PRESSURE TAP

HIGH FIRE ADJUSTMENT

SCREW

(under cap)

WARNING

During blower operation, the ECM motor emits energy that may interfere with pacemaker operation. Interference is reduced by both the sheet metal cabinet and distance.

BEFORE LIGHTING smell all around the appliance area for

gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor.

The gas valve on the SL280DFV unit will be equipped with either a gas control switch. Use only your hand to move the control switch. Never use tools. If the switch will not turn or if the switch will not move by hand, do not try to repair it. Force or attempted repair may result in a fire or explosion.

Placing the furnace into operation:

SL280DFV units are equipped with an automatic ignition system. Do not attempt to manually light burners on these furnaces. Each time the thermostat calls for heat, the burners will automatically light. The ignitor does not get hot when there is no call for heat on units with an automatic ignition system.

WARNING

If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or death.

GAS VALVE SHOWN IN ON POSITION

FIGURE 26

HONEYWELL GAS VALVE

INLET PRESSURE TAP

ON SIDE

GAS VALVE SHOWN IN ON POSITION

FIGURE 27

8 − Move switch on gas valve to ON. Do not force. See fig-

ure 26 or 27. 9 − Replace the access panel.

10 − Turn on all electrical power to to the unit. 11 − Set the thermostat to desired setting.

NOTE − When unit is initially started, steps 1 through 11 may need to be repeated to purge air from gas line.

HIGH FIRE

ADJUSTING SCREW

(under cap)

MANIFOLD

PRESSURE

TAP O N

SIDE

Page 39

12− If the appliance will not operate, follow the instructions

Turning Off Gas to Unit" and call your service technician or gas supplier.

Turning Off Gas to Unit

1 − Set the thermostat to the lowest setting. 2 − Turn off all electrical power to the unit if service is to be

performed.

3 − Remove the upper access panel. 4 − Move switch on gas valve to OF. Do not force. See fig-

ure 26 or 27.

5 − Replace the upper access panel.

Failure To Operate

If the unit fails to operate, check the following: 1 − Is the thermostat calling for heat? 2 − Are access panels securely in place? 3 − Is the main disconnect switch closed? 4 − Is there a blown fuse or tripped circuit breaker? 5 − Is the filter dirty or plugged? Dirty or plugged filters will

cause the limit control to shut the unit off. 6 − Is gas turned on at the meter? 7 − Is the manual main shut-off valve open? 8 − Is the internal manual shut-off valve open? 9 − Is the unit ignition system in lock out? If the unit locks out

again, call the service technician to inspect the unit for

blockages. 10 −Is pressure switch closed? Obstructed flue will cause

unit to shut off at pressure switch. Check flue and outlet

for blockages. 11 −Is the rollout switch tripped? If the switch is tripped call

the service technician to inspect the unit.

Gas Pressure Adjustment

Gas Flow (Approximate)

Furnace should operate at least 5 minutes before checking gas flow. Determine time in seconds for two revolutions of gas through the meter. (Two revolutions assures a more accurate time.) Divide by two and compare to time in table 22 below. If manifold pressure matches table 24 and rate is incorrect, check gas orifices for proper size and restriction. Remove temporary gas meter if installed.

NOTE − Shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to replace pressure tap plug.

TABLE 22

GAS METER CLOCKING CHART

Seconds for One Revolution

SL280

Unit

Natural LP

1 cu ft

Dial

2 cu ft

Dial

1 cu ft

Dial

2 cu ft

DIAL

−045 80 160 200 400

−70 55 11 0 136 272

−90 41 82 102 204

−110 33 66 82 164

−135 27 54 68 136

Natural−1000 btu/cu ft LP−2500 btu/cu ft

Supply Line Pressure

White Rodgers Gas Valve

An inlet post located on the gas valve provides access to the supply pressure. See figure 27. Back out the 3/32 hex screw one turn, connect a piece of 5/16 tubing and connect to a manometer to measure supply pressure. See table 24 for supply line pressure.

Honeywell Gas Valve

A threaded plug on the inlet side of the gas valve provides access to the supply pressure tap. Remove the threaded plug, install a field−provided barbed fitting and connect a manometer to measure supply pressure. See table 24 for supply line pressure. Replace the threaded plug after measurements have been taken.

Manifold Pressure

NOTE − Pressure test adapter kit (10L34) is available from Lennox to facilitate manifold pressure measurement.

1 − Connect test gauge to manifold pressure post (figure

26) or tap (figure 27) on gas valve.

2 − Ignite unit on high fire and let run for 5 minutes to allow

for steady state conditions.

3 − After allowing unit to stabilize for 5 minutes, record

manifold pressure and compare to value given in table

24.

4 − If necessary, make adjustments. Figures 26 and 27

show location of high fire adjustment screw.

5 − If an adjustment is made on high fire, re−check man-

ifold pressure on low fire. Do not adjust low fire man- ifold pressure. If low fire manifold pressure is more than 1/2" above or below value specified in table 24, replace valve.

Proper Combustion

Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking combustion. Table 23 shows acceptable combustion for ALL SL280DFV models.

TABLE 23

Firing Rate

High Fire 6.0 − 7.4 6.9 − 8.4

Low Fire 4.8 − 6.0 5.7 − 7.0

The carbon monoxide reading should not exceed 50 ppm.

CO2%

For Nat

CO2%

For L.P.

Page 40

High Altitude

The manifold pressure, gas orifice and pressure switch may require adjustment or replacement to ensure proper operation at higher altitudes. Tables 24 through 27 shows manifold pressure, pressures switch and gas conversion kits at all altitudes.

TABLE 24

Manifold Pressure Settings

IMPORTANT

For safety, shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to replace pressure tap plug.

Unit

Input

Gas

Orifice Size

0 − 7500 ft.

Orifice Size

7501 −

10,000 ft.

Manifold

Pressure in.wg.

0−4500 ft.

Low

Fire

High

Fire

Manifold

Pressure in.wg.

4501−7500 ft.

Low

Fire

High

Fire

Manifold

Pressure in.wg.

7501 − 10,000 ft.

Low

Fire

High

Fire

Supply Line

Min Max

Pressure

in. w.g.

Natural .063 .055 1.7 3.5 1.6 3.4 1.7 3.5 4.5 13.0

070

LP/propane

.039 .037 4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0

Natural .063 .055 1.7 3.5 1.5 3.0 1.7 3.5 4.5 13.0

090

LP/propane

.039 .037 4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0

Natural .063 .055 1.7 3.5 1.5 3.2 1.7 3.5 4.5 13.0

110

This is the only permissible derate for these units.

Natural gas high altitude orifice kit required.

A natural to L.P. propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction for the conversion

procedure.

NOTE − Units may be installed at altitudes up to 4500 ft. above sea level without modifications.

LP/propane

.039 .037 4.9 10.0 4.9 10.0 4.9 10.0 11.0 13.0

TABLE 25

High Altitude Pressure Switch Kits

Unit

Input

070 No Change No Change 73W36

090 No Change 69W56 73W36

110 No Change 69W56 73W35

0 − 4500 ft. 4501 − 7500 ft. 7501 − 10,000 ft.

High Altitude

Pressure Switch Kit

TABLE 26

Honeywell Gas Valve Conversion Kits

High Altitude

Natural Gas

Unit

Input

070 73W37 51W02 73W38 69W79

090 73W37 51W02 73W38 69W79

110 73W37 51W02 73W38 69W79

Orifice Kit

7501 −

10,000 ft.

Natural Gas to

LP/ Propane Kit

0 − 7500 ft.

7501 −

10,000 ft.

LP/Propane

Natural Gas

Kit

0 − 7500 ft.

Page 41

TABLE 27

White Rodgers Gas Valve Conversion Kits

High Altitude

Unit

Input

070 77W05 77W07 77W11 77W09

090 77W05 77W07 77W11 77W09

110 77W05 77W07 77W11 77W09

Natural Gas

Orifice Kit

7501 −

10,000 ft.

Natural Gas to

LP/ Propane Kit

0 − 7500 ft.

7501 −

10,000 ft.

LP/Propane

Natural Gas

Kit

0 − 7500 ft.

Other Unit Adjustments

Primary and Secondary Limits

The primary limit is located on the heating compartment vestibule panel. The secondary limits (if equipped) are located in the blower compartment, attached to the back side of the blower. These limits are factory set and require no adjustment.

Flame Rollout Switch

This manually reset switch is located on the burner box. If tripped, check for adequate combustion air before resetting.

Pressure Switches

The pressure switch assembly (includes two switches) is located in the heating compartment adjacent to the combustion air inducer. These switches check for proper combustion air inducer operation before allowing ignition trial. The switches are factory−set and require no adjustment.

Temperature Rise

Place the unit into operation with a second−stage heating demand. After supply and return air temperatures have stabilized, check the temperature rise. If necessary, adjust the heating blower speed to maintain the temperature rise within the range shown on the unit nameplate. Increase the blower speed to decrease the temperature rise. Decrease the blower speed to increase the temperature rise. Failure to properly adjust the temperature rise may cause erratic limit operation and may result in premature heat exchanger failure.

Thermostat Heat Anticipation

Set the heat anticipator setting (if adjustable) according to the amp draw listed on the wiring diagram that is attached to the unit.

Heating Sequence of Operation

Electronic Ignition

The two−stage, variable speed integrated control used in SL280DFV units has an added feature of an internal Watchguard control. The feature serves as an automatic reset device for ignition control lockout caused by ignition failure. This type of lockout is usually due to low gas line pressure. After one hour of continuous thermostat demand for heat, the Watchguard will break and remake thermostat demand to the furnace and automatically reset the control to begin the ignition sequence.

NOTE − The integrated control thermostat selection DIP switch is factory−set in the TWO−STAGE" position.

Applications Using a Two−Stage Thermostat

See figure 28 for ignition control sequence A − Heating Sequence −− Integrated Control Thermostat Selection DIP Switch 1 OFF in Two−Stage" Position (Factory Setting)

1 − On a call for heat, thermostat first−stage contacts close

sending a signal to the integrated control. The integrated control runs a self-diagnostic program and checks high temperature limit switches for normally closed contacts and pressure switches for normally open contacts. The combustion air inducer is energized at low speed.

2 − Once the control receives a signal that the low pres-

sure switch has closed, the combustion air inducer begins a 15−second pre−purge in low speed.

NOTE − If the low fire pressure switch does not close the combustion air inducer will switch to high fire. After a 15 second pre−purge the high fire pressure switch will close and the unit will begin operation on high fire. After 10 to 20 seconds of high fire operation the unit will switch to low fire..

3 − After the pre−purge is complete, a 20−second initial ig-

nitor warm−up period begins. The combustion air inducer continues to operate at low speed.

4 − After the 20−second warm−up period has ended, the gas

valve is energized on low fire (first stage) and ignition occurs. At the same time, the control module sends a signal to begin an indoor blower 30−second ON−delay. When the delay ends, the indoor blower motor is energized on the low fire heating speed, the HUM contacts close energizing the humidifier and 120V ACC terminal is energized. The furnace will continue this operation as long as the thermostat has a first−stage heating demand.

5 − If second−stage heat is required, the thermostat sec-

ond−stage heat contacts close and send a signal to the integrated control. The integrated control initiates a 30−second second−stage recognition delay.

6 − At the end of the recognition delay, the integrated con-

trol energizes the combustion air inducer at high speed. The control also checks the high fire (second stage) pressure switch to make sure it is closed. The high fire (second stage) gas valve is energized and the indoor blower motor is energized for operation at the high fire heating speed.

7 − When the demand for high fire (second stage) heat is

satisfied, the combustion air inducer is switched to the low−fire heating speed and the high−fire (second stage) gas valve is de−energized. The low−fire (first stage) gas valve continues operation. The indoor blower motor is switched to the low−fire heating speed.

8 − When the thermostat demand for low−fire (first stage)

heat is satisfied, the gas valve is de−energized and the field−selected indoor blower off delay begins. The combustion air inducer begins a 5−second post−purge period.

9 − When the combustion air post−purge period is com-

plete, the inducer, the HUM contacts as well as the 120V ACC terminals are de−energized. The indoor blower is de−energized at the end of the off delay.

Page 42

Applications Using A Single−Stage Thermostat

See figure 29 for ignition control sequence

B − Heating Sequence −− Control Thermostat Selection DIP Switch 1 ON in Single−Stage" Position

NOTE − In these applications, two−stage heat will be initiated by the integrated control if heating demand has not been satisfied after the field adjustable period (7 or 12 minutes).

1 − On a call for heat, thermostat first−stage contacts close

2 − Once the control receives a signal that the low pres-

sure switch has closed, the combustion air inducer begins a 15−second pre−purge in low speed.

3 − After the pre−purge is complete, a 20−second initial ig-

nitor warm−up period begins. The combustion air inducer continues to operate at low speed.

4 − After the 20−second warm−up period has ended, the gas

valve is energized on low fire (first stage) and ignition occurs. At the same time, the control module sends a signal to begin an indoor blower 30−second ON−delay. When the delay ends, the indoor blower motor is energized on the low fire heating speed and the HUM contacts are energized. The integrated control also initiates a second−stage on delay (factory−set at 7 minutes; adjustable to 12 minutes).

5 − If the heating demand continues beyond the second−

stage on delay, the integrated control energizes the combustion air inducer at high speed. The control also checks the high fire (second stage) pressure switch to make sure it is closed. The high fire (second stage) gas valve is energized and the indoor blower motor is energized for operation at the high fire heating speed.

6 − When the thermostat heating demand is satisfied, the

combustion air inducer begins a 5−second low speed post−purge. The field−selected indoor blower off delay begins. The indoor blower operates at the low−fire heating speed.

7 − When the combustion air post−purge period is com-

plete, the inducer, the HUM contacts as well as the 120V ACC terminals are de−energized. The indoor blower is de−energized at the end of the off delay.

OFF

1 stg heat demand

low speed CAI ignitor

low fire gas valve

indoor blower low heat

2 stg heat demand high speed CAI high fire gas valve

indoor blower high heat

* Conventional thermostat 30 seconds, icomfort Touch® thermostat set for 30 adjustable 15 to 45 seconds.

OFF

heat demand

low speed CAI ignitor low fire gas valve

indoor blower low heat

Pre−Purge

HEATING OPERATION WITH TWO−STAGE THERMOSTAT

Trial For Ignition

30 seconds

30* second

blower

on" delay

RECOGNITION PERIOD

Pre−Purge

Ignitor Warm−up

FIGURE 28

HEATING OPERATION WITH SINGLE STAGE THERMOSTAT

Ignitor Warm−up

Trial For Ignition

30* second

blower

on" delay

5 SEC80

Post

Purge

5 SEC

Post

Purge

blower

off"

delay

blower

off"

delay

7 or 12 minutes after heating demand begins, furnace switches to high fire (depends on setting)

high speed CAI high fire gas valve

indoor blower high heat

* Conventional thermostat 30 seconds, icomfort Touch

thermostat set for 30 adjustable 15 to 45 seconds.

FIGURE 29

Page 43

Service

WARNING

ELECTRICAL SHOCK, FIRE,

OR EXPLOSION HAZARD.

Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage. Improper servicing could result in dangerous operation, serious injury, death, or property damage. Before servicing, disconnect all electrical power to furnace. When servicing controls, label all wires prior to disconnecting. Take care to reconnect wires correctly. Verify proper operation after servicing.

At the beginning of each heating season, a licensed professional technician (or equivalent) should check the system as follows:

Blower

Check the blower wheel for debris and clean if necessary. The blower motors are prelubricated for extended bearing life. No further lubrication is needed.

WARNING

Filters

All SL280DFV filters are installed external to the unit. Filters should be inspected monthly. Clean or replace the filters when necessary to ensure that the furnace operates properly. Replacement filters must be rated for high velocity airflow. Table 3 lists recommended filter sizes.

Flue And Chimney

1 − Check flue pipe, chimney and all connections for tight-

ness and to make sure there is no blockage.

2 − Check unit for proper draft.

Electrical

1 − Check all wiring for loose connections. 2 − Check for the correct voltage at the furnace (furnace

operating). Correct voltage is 120VAC +

3 − Check amp−draw on the blower motor with inner blow-

er access panel in place. Unit Nameplate__________Actual__________

Cleaning the Heat Exchanger and Burners

NOTE − Use papers or protective covering in front of the furnace during cleaning.

1 − Turn off both electrical and gas power supplies to fur-

nace.

2 − Remove flue pipe, top cap, flue chase and internal flue

pipe assembly from the unit.

3 − Label the wires from gas valve, rollout switches, prima-

ry limit switch and make−up box then disconnect them.

4 − Remove the screws that secure the combustion air in-

ducer/pressure switch assembly to the collector box. Carefully remove the combustion air inducer to avoid damaging blower gasket. If gasket is damaged, it must be replaced to prevent leakage.

5 − Remove the collector box located behind the combus-

tion air inducer. Be careful with the collector box gasket. If the gasket is damaged, it must be replaced to prevent leakage.

6 − Disconnect gas supply piping. Remove the screw se-

curing the burner box cover and remove cover. Remove the four screws securing the burner manifold assembly to the vestibule panel and remove the assembly from the unit.

7 − Remove screws securing burner box and remove

burner box.

8 − Remove screws from both sides, top and bottom of

vestibule panel.

9 − Remove heat exchanger. It may be necessary to

spread cabinet side to allow more room. If so, remove five screws from the left side or right side of cabinet. See figure 31.

10− Back wash using steam. Begin from the burner opening

on each clam. Steam must not exceed 275°F.

11− To clean burners, run a vacuum cleaner with a soft brush

attachment over the face of burners. Visually inspect inside the burners and crossovers for any blockage caused by foreign matter. Remove any blockage. Figure 30 shows burner detail.

10%.

Page 44

gasket

flue chase

internal flue pipe

combustion air inducer

rollout switch

burner box assembly

sensor

gasket

SL280DFV BURNER, COMBUSTION AIR INDUCER ASSEMBLY &

HEAT EXCHANGER REMOVAL

orifice plate

gasket

ignitor

pressure switch

burners

manifold and gas valve

collector box

retention rings

heat exchanger

burner box cover plate

cross over

FIGURE 30

Page 45

12− To clean the combustion air inducer visually inspect and

using a wire brush clean where necessary. Use compressed air to clean off debris and any rust.

13− Reinstall heat exchanger in vestibule. (Replace the

five screws in the cabinet from step 10 if removed).

14− Reinstall collector box, combustion air assembly, inter-

nal flue pipe and flue chase. Seal with high tempera- ture RTV. Reinstall all screws to the collector box and combustion air inducer. Failure to replace all screws may cause leaks. Inspect gaskets for any damage and replace if necessary.

15− Reinstall burner box, manifold assembly and burner box

cover.

16− Reconnect all wires.

17− Reconnect top cap and vent pipe to combustion air in-

ducer outlet.

18− Reconnect gas supply piping.

19− Turn on power and gas supply to unit.

20− Set thermostat and check for proper operation.

20− Check all piping connections, factory and field, for gas

leaks. Use a leak detecting solution or other preferred means.

22− Repeat steps 21 and 23 until no leaks are detected.

23− Replace access panel.

Remove five screws if necessary

(either side of cabinet)

CAUTION

21− If a leak is detected, shut gas and electricity off and

repair leak.

FIGURE 31

Page 46

Planned Service

The following items should be checked during an annual inspection. Power to the unit must be shut off for the service technician’s safety.

Fresh air grilles and louvers (on the unit and in the room where the furnace is installed) − Must be open and unobstructed to provide combustion air.

Operating performance − Unit must be observed during operation to monitor proper performance of the unit and the vent system.

Burners − Must be inspected for rust, dirt, or signs of water.

Vent pipe − Must be inspected for signs of water, damaged

or sagging pipe, or disconnected joints.

Unit appearance − Must be inspected for rust, dirt, signs of water, burnt or damaged wires, or components.

Blower access door − Must be properly in place and provide a seal between the return air and the room where the furnace is installed.

Return air duct − Must be properly attached and provide an air seal to the unit.

Combustion gases − Flue products must be analyzed and compared to the unit specifications.

Problems detected during the inspection may make it necessary to temporarily shut down the furnace until the items can be repaired or replaced.

Instruct the homeowners to pay attention to their furnace. Situations can arise between annual furnace in-

spections that may result in unsafe operation. For instance, items innocently stored next to the furnace may obstruct the combustion air supply. This could cause incomplete combustion and the production of carbon monoxide gas.

Repair Parts List

The following repair parts are available through independent Lennox dealers. When ordering parts, include the complete furnace model number listed on the CSA International nameplate −− Example: SL280DF070V36A.

All service must be performed by a licensed professional installer (or equivalent), service agency, or gas supplier.

Cabinet Parts

Upper access panel Blower panel Top cap

Control Panel Parts

Transformer Two−stage, variable speed integrated control Door interlock switch Circuit breaker

Blower Parts

Blower wheel Blower housing Motor Motor electronics Power choke (1 hp only) Motor mounting frame Blower housing cutoff plate

Heating Parts

Flame Sensor

Heat exchanger assembly Gas manifold Two−speed combustion air inducer Two−stage gas valve Main burner cluster Main burner orifices Pressure switch Ignitor Primary limit control Flame rollout switch

Secondary limit

Page 47

Integrated Control Diagnostic Modes

Display Action (when button released)

No change (idle)* Remain in idle mode

Solid E" Enter diagnostic recall mode

Solid D" Discharge Air Installed

Solid F" Enter flame signal mode

Solid P" (variable speed only) Program unit capacity/size (Unit Code)**

* No change implies the display will continue to show whatever is currently being displayed for normal operation (blinking decimal, active error code, heat state, etc..)

** After the P" is selected (by releasing the push button) the integrated control will start flashing the P" on display for 90 seconds. If push button is pressed again and held during that time, the control will start to display characters corresponding to different variable speed furnace models for 3 seconds each. While the wanted character−model is displayed push button has to be released. Selected option will flash display for 10 seconds and during that time push button has to be pressed and held for 5 seconds. Once control accepts new setting it will store data in non−volatile memory and reset itself. If 10 seconds expires or push button is held less than 5 seconds, control will exit filed test mode and go in idle without programming the unit size.

Integrated Control Diagnostic Codes

Press the diagnostic push button and hold it to cycle through a menu of options. Every five seconds a new menu item will be displayed. Release the button when the desired mode is displayed. When a solid "P" is displayed, the furnace capacity / size is programmed. When the solid E" is displayed, the control enters the Diagnostic Recall (Alarm History). Diagnostic Recall mode menu options: No change (displaying error history) remains in Diagnostic Recall mode; solid  = and solid c" clears the error history. Must press button while flashing c" is displayed to clear error codes. When the solid F" is displayed, the control enters the Flame Signal Mode. The Flame Signal Mode is exited: with power cycle/reset, by pressing and holding the push button until 3 horizontal line are displayed = flame signal mode.

" exits Diagnostic Recall mode;

, after 10 minutes of entering

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

Idle mode (Decimal blinks at 1 Hertz −− 0.5 second ON, 0.5 second OFF).

Cubic feet per minute (cfm) setting for indoor blower (1 second ON, 0.5 second OFF) / cfm setting for current mode displayed.

Cooling stage (1 second ON, 0.5 second OFF) / 1 or 2 displayed / Pause / cfm setting displayed / Pause / Repeat codes).

Dehumidification mode (1 second ON) / 1 second OFF) / cfm setting displayed / Pause / Repeat Codes).

Heat pump stage (1 second ON, 0.5 second OFF) / % of input rate displayed / Pause / cfm setting / Pause / Repeat codes.

Gas Heat Stage (1 second ON, 0.5 second OFF) / 1 or 2 displayed / Pause / cfm setting displayed / Pause / Repeat codes. Blinking during ignition.

Defrost mode.

Discharge Air Temperature

Page 48

Integrated Control Diagnostic Codes (continued)

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

E 105

Device communication problem − No other devices on RS BUS (Communication system).

E 110

Low line voltage. Line Voltage Low (Voltage lower than nameplate

E 111

Line voltage polarity reversed. Reverse line power voltage wiring. System resumes

E 112

Ground not detected System shuts down. Provide proper earth ground.

E 113

High line voltage. Line Voltage High (Voltage higher than nameplate

E 114

Line voltage frequency out−of−range. No 60 Hertz Power. Check voltage and line power

E 115

Low 24V − Control will restart if the error recovers. 24−Volt Power Low (Range is 18 to 30 volts). Check

E 116

High 24V. 24 Volt Power High (Range is 18 to 30 volts). Check

E 117

Poor ground detected (Warning only) Provide proper grounding for unit. Check for proper

E 120

Unresponsive device. Communication only. Usually caused by delay in outdoor unit responding

E 124

Active communicating thermostat signal missing for more than 3 minutes.

E 125

Control failed self−check, internal error, failed hardware. Will restart if error recovers. Integrated control not communicating. Covers hardware errors (flame sense circuit faults, pin shorts, etc.).

E 126

Control internal communication problem. Hardware problem on the control. Cycle power on

Equipment is unable to communicate. Indicates numerous message errors. In most cases errors are related to electrical noise. Make sure high voltage power is separated from RSBus. Check for mis− wired and/or loose connections between the stat, indoor unit and outdoor unit. Check for a high voltage source of noise close to the system. Fault clears after communication is restored.

rating). Check power line voltage and correct. Alarm clears 5 seconds after fault recovered.

normal operation 5 seconds after fault recovered.

System resumes normal operation 5 seconds after fault recovered.

rating). Provide power voltage within proper range. System resumes normal operation 5 seconds after fault recovered.

frequency. Correct voltage and frequency problems. System resumes normal operation 5 seconds after fault recovered.

and correct voltage. Check for additional power−robbing equipment connected to system. May require installation of larger VA transformer to be installed in furnace / air handler. Clears after fault recovered.

and correct voltage. Check for proper line voltage (120V, 240V, etc.) to equipment. Clears when control senses proper voltage.

earth ground to the system. Warning only will clear 30 seconds after fault recovered.

to indoor unit poling. Recycle power. Check all wiring connections. Cleared after unresponsive device responds to any inquiry.

Equipment lost communication with the thermostat. Check four wiring connections, ohm wires and cycle power at the thermostat. Alert stops all services and waits for heartbeat message from thermostat (subnet controller). Cleared after valid thermostat (subnet controller) message is received.

Hardware problem on the control. Cycle power on control. Replace if problem prevents service and is persistent. Critical alert. Cleared 300 seconds after fault recovered.

control. Replace if problem prevents service and is persistent. Cleared 300 seconds after fault recovered.

Page 49

Integrated Control Diagnostic Codes (continued)

E 131

Corrupted control parameters (Verify configuration of system). Communicating only.

E 180

Outdoor air temperature sensor failure. Only shown if shorted or out−of− range.

E 200

Hard lockout − Rollout circuit open or previously open. Correct cause of rollout trip, or replace flame rollout

E 201

Indoor blower communication failure − Unable to communicate with blower motor.

E 202

Indoor blower motor mis−match − Indoor motor horsepower does not match unit capacity. See Page 55.

E 203

Appliance capacity / size is NOT programmed. Invalid unit codes refer to configuration flow chart. See Page 55.

E 204

Gas valve mis−wired. Check gas valve operation and wiring. Clears when

E 205

Gas valve control relay contact shorted. Check wiring on control and gas valve. If wiring is

E 206

Gas valve second−stage relay failure Furnace will operate on 1st stage for remainder of

E 207

Hot surface ignitor sensed open − Refer to troubleshooting. See Page 56. Measure resistance of hot surface ignitor. Replace if

Reconfigure the system. Replace control if heating or cooling is not available. Only applicable in the communicating mode, not in startup. Exit from Commissioning and Execute ’Set Factory Default mode’. Control will still operate on default parameter settings.

Compare outdoor sensor resistance to temperature/ resistance charts in unit installation instructions. Replace sensor pack if necessary. At beginning of (any) configuration, furnace or air handler control will sense outdoor air and discharge air temperature sensor(s). If detected (reading in range), appropriate feature will be set as ’installed’ and that could be seen in ’About’ screen. In normal operation after control recognizes sensors, alarm will be sent if valid temperature reading is lost. To get rid of setting and alarm, redo configuration and make sure that temperature sensor is marked as ’not installed’ in Indoor Unit ’About’ screen. When Indoor unit control is replaced, thermostat will ’tell’ new control if temperature sensor is in system or not. Clears 30 seconds after fault recovered.

switch. Test furnace operation. Cleared after fault recovered.

Indoor blower communication failure (including power outage). Lost communication with indoor blower motor. Possible causes: motor not powered, loose wiring. Problem may be on control or motor side. Cleared after fault recovered.

Incorrect appliance capacity code selected. Check for proper configuring under: Unit Size Codes for Furnace/Air Handler on configuration guide or in installation instructions. Cleared after the correct match is detected following a reset. (Remove thermostat from system while applying power and reprogramming.)

No appliance capacity code selected. Check for proper configuring under: Unit Size Codes for Furnace on configuration guide or in installation instructions. Critical Alert. Cleared after valid unit code is read following a reset. (Remove thermostat from system while applying power and reprogramming.)

repaired.

correct, replace control.

the heating demand. Will clear after fault recovered. If unable to operate 2nd stage, replace control.

open or not within specified range found in IOM. Resumes normal operation after fault is cleared.

Page 50

Integrated Control Diagnostic Codes (continued)

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

E 223

E 224

E 225

E 226

E 227

E 228

E 229

E 240

E 241

E 250

E 252

E 270

E 271

Low pressure switch failed open. Check pressure (inches w.c.) of low pressure switch

closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared

Low pressure switch failed closed − Refer to troubleshooting. See Page 56.

High pressure switch failed open − Refer to troubleshooting. See Page 56.

High pressure switch failed closed − Refer to troubleshooting. See Page 56.

Low pressure switch open during trial for ignition or run mode. Refer to troubleshooting. See Page 56.

Combustion air inducer calibration failure Unable to perform pressure switch calibration.

Ignition on high fire IFC switched to high fire ignition because low fire

Low flame current − Run mode − Refer to troubleshooting. See Page 56. Check micro−amperes of flame sensor using control

Flame sensed out of sequence − Flame still present. Shut off gas. Check for gas valve leak. Replace, if

Limit switch circuit open − Refer to troubleshooting. Check for proper firing rate on furnace. Ensure

Discharge air temperature too high (gas heat only). Check temperature rise, air flow and input rate.

Soft lockout − Exceeded maximum number of retries. No flame current sensed.

Soft lockout − Exceeded maximum number of retries. Last retry failed due to the pressure switch opening.

Check operation of low pressure switch to see if it is stuck closed on heat call longer than 150 seconds. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.

Check pressure (inches w.c.) of high pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.

Check operation of high pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.

Check pressure (inches w.c.) of low pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.

Check vent system and pressure switch wiring connections. Resumes normal operation after fault is cleared.

pressure switch did not close in allowed time. No action is needed.

diagnostics or field−installed mode. Clean or replace sensor. Measure voltage of neutral to ground to ensure good unit ground. Alert clears after current heat call has been completed.

necessary. Alert clears when fault is recovered.

there is no blockage in heater. Check for proper air flow. If limit not closed within 3 minutes, unit will go into 1−hour soft lockout. Resumes normal operation after fault is cleared.

Cleared when heat call is finished.

Check for proper gas flow. Ensure that ignitor is lighting burner. Check flame sensor current. Clears when heat call finishes successfully.

Page 51

Integrated Control Diagnostic Codes (continued)

E 272

E 273

E 274

E 275

E 276

E 290

E 291

E 292

E 294

E 295

E 310

E 311

Soft lockout − Exceeded maximum number of recycles. Last recycle due to the pressure switch opening.

Soft lockout − Exceeded maximum number of recycles. Last recycle due to flame failure.

Soft lockout − Exceeded maximum number of recycles. Last recycle failed due to the limit circuit opening or limit remained open longer than 3 minutes.

Soft lockout − Flame sensed out of sequence. Flame signal is gone. Shut off gas. Check for gas valve leak. 1−hour soft

Watchguard calibration failure. Unable to perform pressure switch calibration.

Ignitor circuit fault − Failed ignitor or triggering circuitry. Measure resistance of hot surface ignitor. Replace if

Heat air flow restricted below the minimum. Check for dirty filter and air flow restriction. Check

Indoor blower motor unable to start due to obstructed wheel, seized bearings.

Combustion air inducer over current. Check combustion blower bearings, wiring and

Indoor blower motor temperature is too high. Indoor blower motor over temperature (motor

Discharge error temperature sensor failure. Only shown if shorted or out of range.

Heat rate reduced to match indoor blower air flow. Warning Only. Furnace blower in cutback mode due

Check operation of low pressure switch to see if it is stuck closed on heat call. Check pressure (inches w.c.) of high pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Clears when heat call finishes successfully.

Check micro−amperes of flame sensor using control diagnostics or field−installed mode. Clean or replace sensor. Measure voltage of neutral to ground to ensure good unit ground. Clears when heat call finishes successfully.

Shut down system. 1−hour soft lockout. Check firing rate and air flow. Check for blockage. Clears when heat call finishes successfully.

lockout. Clears when flame has been proven stable.

Check vent system and pressure switch wiring connections. 1−hour soft lockout. Clears when calibration has finished successfully.

open or not within specifications. 1−hour soft lockout. Clears when flame has been proven stable.

blower performance. 1−hour soft lockout. Cleared when heat call finishes successfully.

Indoor blower motor unable to start (seized bearing, stuck wheel, etc.). Replace motor or wheel if assembly does not operate or meet performance standards. 1−hour soft lockout. Clears after circulator successfully starts.

amps. Replace if does not operate or does not meet performance standards. Clears after inducer current is sensed to be in−range after the ignition following the soft lockout or reset.

tripped on internal protector). Check motor bearings and amps. Replace if necessary. Cleared after blower demand is satisfied.

Compare outdoor sensor resistance to temperature/ resistance charts in installation instructions. Replace sensor if necessary. Cleared in Communicating mode: 30 seconds after fault recovered. In Non− Communicating mode: Cleared after the current heat call is completed.

to restricted airflow. Reduce firing rate every 60 seconds to match available CFM. Check filter and duct system. To clear, replace filter if needed or repair/add duct. 2−stage controls will reduce firing rate

stage. Clears when heat call finishes success-

to 1 fully.

Page 52

Integrated Control Diagnostic Codes (continued)

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

E 312

E 313

E 331

E 334

E 347

E 348

E 349

E 370

E 400

E 401

E 402

E 403

E 404

E 405

Restricted air flow in cooling or continuous fan mode is lower than cfm setting.

Indoor or outdoor unit capacity mismatch. Communication only. Incorrect indoor/outdoor capacity code selected.

Global network connection − Communication link problem. For Future Use.

Relay Y1" stuck on interated control. Replace integrated control.

No 24 Volt output on Y1 of "integrated control" with non communicating outdoor unit.

No 24 Volt output on Y2 of "integrated control" with non?communicating outdoor unit.

No 24 Volts between R & O on "integrated control" with non communicating outdoor unit (Dual fuel module required for heat pump application).

Interlock switch sensed open for 2 minutes. Control sees the loss of 24VAC for 2 minutes .Ter-

LSOM − Compressor internal overload tripped. Thermostat demand Y1 is present; but, compressor

LSOM Compressor long run cycle or low system pressure. Compressor ran more than 18 hours to satisfy a

LSOM − Outdoor unit system pressure trip. Discharge or suction pressure out−of−limits, or com-

LSOM − Compressor short−cycling. .(Running less than 4 minutes). Outdoor unit pressure trip

LSOM − Compressor rotor locked. Compressor short−cycling. (Running less than 4 minutes).

LSOM − Compressor open circuit. Compressor circuit open (due to power disconnec-

Warning Only. Restricted airflow − Indoor blower is running at a reduced CFM (Cutback Mode − The variable speed motor has pre−set speed and torque limiters to protect the motor from damage caused by operating outside of design parameters (0 to 0.8" W.C.. total external static pressure). Check filter and duct system. To clear, replace filter if needed or repair/add duct. Cleared after the current service demand is satisfied.

Check for proper configuring in installation instructions. Alarm is just a warning. The system will operate, but might not meet efficiency and capacity parameters. Alarm will clear when commissioning is exited. Cleared after commissioning is complete.

Operation stopped. Y1 relay / Stage 1 failed. (Pilot relay contacts did not close or the relay coil did not energize; no input back to IFC chip). Critical Alert. Cleared after reset and Y1 input sensed.

Y2 relay / Stage 2 failed. (Pilot relay contacts did not close or the relay coil did not energize; no input back to IFC chip). Critical Alert. Cleared after reset and Y1 input sensed.

Configuration link R to O needs to be restored. Replace link or hard−wire. Applicable in non communicating mode. Critical Alert.

minate all services and wait for interlock switch to close. The alarm will clear when 24VAC is continuously sensed on DS terminal for a minimum of 10 seconds or on a power reset.

is not running. Check power to outdoor unit. Clears the error after current is sensed in both RUN and START sensors for at least 2 seconds, or after service is removed, or after power reset.

single thermostat demand. Critical Alert. Clears the error after 30 consecutive normal run cycles or power reset. Also monitors low pressure switch trips.

pressor overloaded. Clears the error after 4 consecutive normal compressor run cycles.

Compressor runs less than 3 minutes to satisfy a thermostat demand. Clears the error after 4 consecutive normal run cycles or power reset.

Compressor rotor locked up due to run capacitor short, bearings are seized, excessive liquid refrigerant, etc. Clears the error after 4 consecutive normal run cycles or after power reset.

tion, open fuse, etc.) Clears the error after 1 normal compressor run cycle.

Page 53

Integrated Control Diagnostic Codes (continued)

E 406

E 407

E 408

E 409

LSOM − Compressor open start circuit. Required amount of current is not passing through

Start current transformer. Clears the error after current is sensed in START sensor, or after power reset.

LSOM − Compressor open run circuit. Required amount of current is not passing through

Run current transformer. Clears the error after current is sensed in RUN sensor, or 1 normal compressor run cycle, or after power reset.

LSOM − Compressor contactor is welded. Compressor runs continuously. Clears the error

after 1 normal compressor run cycle or after power reset.

LSOM − Compressor low voltage. Secondary voltage is below 18VAC. After 10 min-

utes, operation is discontinued. Clears the code after voltage is higher than 20 VAC for 2 seconds or after power reset.

Page 54

Program Unit Capacity/Size Mode

Power−Up − Number displayed represents by integrated control unit size code (furnace model

and capacity). If three horizontal bars are displayed followed by continuous E203, furnace control does not recognize unit size code. Configure per the following:

Yes

To enter Program Unit Capacity/Size: push and hold button next to 7−segment LED display until solid P" symbol appears. Release button.

IMPORTANT: Field replacement controls may need to be manually configured to validate furnace unit size code.

Solid P starts blinking on 7−Segment LED

Furnace control in IDLE mode

No heating, cooling or indoor fan

operation)

UNIT SIZE

CODE

−

Turn room thermostat to OFF

FURNACE MODEL

SL280DF070V36A

SL280DF090V48B

SL280DF090V60C

SL280DF110V60C

Push and hold button. Integrated control will display unit size code number for each furnace model for three seconds.

When the correct unit size code is displayed, release button. Selected code will flash for 10−second period. During that period, press and hold push button for 5 seconds. Integrated control will store code in memory and will automatically exit Program Unit Capacity/Size Mode and reset. (If second period expires or push button is held less than five seconds, control will automatically exit Program Capacity/Size Mode and go into IDLE mode without storing unit size code. If this happens, programming function must be repeated).

−

. If

−

Verify that the selected unit size code is correct and stored in non−volatile memory by cycling the 24 volt power to the furnace control. (At 24 volt power−up of the furnace control, the 7−segment LED will display a unit size code three horizontal bars display, board does not recognize unit size code function must be repeated)

. Programming

FINISHED

Page 55

Troubleshooting: Heating Sequence of Operation

CALL FOR FIRST−STAGE HEAT

CALL FOR

1ST STAGE HEAT

(LOW FIRE)

LIMIT SWITCH

ROLLOUT

PRESSURE

INDUCER ON

LOW SPEED

PRESSURE SWITCH CLOSED WITHIN 120

SECONDS?

PRE−PURGE

(15 SECONDS)

H.S.I. ON

(20 SECONDS)

1ST STAGE GAS

VALVE ENERGIZED

IGNITION TRIAL

BEGINS (H.S.I. ON)

HIGH

CLOSED?

YES

CIRCUITS CLOSED?

YES

LOW

SWITCH

OPEN?

YES

LOW

YES

HEAT FAN ON DELAY

TIMER STARTED

INDOOR BLOWER OFF AFTER

HEAT FAN OFF DELAY

(LOW HEAT SPEED)

ERROR

CODE

FLASHES

DE−ENERGIZE

GAS VALVE

ERROR CODE

FLASHES (AFTER

5 SECONDS)

LOW PRESSURE SWITCH OPENS

HIGH

PRESSURE

SWITCH

OPEN

BEFORE

INDUCER WAS

TURNED ON?

INDOOR BLOWER

ON(LOW HEAT

SPEED)

INDUCER ON

(HIGH SPEED)

INDOOR BLOWER

ON (LOW HEAT

SPEED)

INTERPURGE

(15 SECONDS)

YES

CLOSED WITHIN 3

MINUTES?

INDUCER TO

HIGH SPEED−

ERROR CODE

FLASHES

LIMIT

SWITCH

ERROR

CODE

FLASHES

INDOOR

BLOWER OFF

AFTER HEAT FAN

OFF DELAY (LOW

HEAT SPEED)

ROLLOUT

CIRCUIT CLOSES

(MANUAL

RE−SET)

INDUCER OFF

AFTER POST

PURGE

INDOOR BLOWER OFF AFTER HEAT OFF DELAY

HARD LOCKOUT − ERROR CODE FLASHES

LOW & HIGH

PRESSURE SWITCH

CLOSED WITHIN 30

SECONDS?

YES

WATCHGUARD − ERROR CODE FLASHES

YES

INDUCER OFF−

WAIT

5 MINUTES

ERROR CODE

FLASHES

CALL

FOR HEAT

ENDS?

YES

INDOOR

BLOWER

ON?

YES

INDOOR

BLOWER

OFF AFTER

HEAT FAN

OFF DELAY

FLAME

SENSED WITHIN

4 SECONDS?

YES

H.S.I. OFF

INDOOR

BLOWER ON 45 SEC.

(LOW HEAT SPEED)

CALL FOR HEAT SATISFIED

GAS VALVE

DE−ENERGIZED

H.S.I. OFF

WATCHGUARD LOCKOUT AUTOMATICALLY RESETS AFTER ONE HOUR

HARD LOCKOUT REQUIRES THERMOSTAT RESET OR CYCLING OF POWER TO RESET THE LOCKOUT.

IN CASE HIGH SPEED INDUCER IS RUNNING AT THE TIME THE GAS VALVE GETS ENERGIZED,

2ND STAGE GAS VALVE IS ENERGIZED INSTEAD OF 1ST STAGE. 20 SECONDS AFTER FLAME IS SENSED, INDUCER SWITCHES TO LOW SPEED, AND GAS VALVE SWITCHES TO 1ST STAGE.

5TH

UNSUCCESSFUL

TRIAL?

YES

Page 56

POSTPURGE (5 SECONDS)

INDUCER

OFF

WATCHGUARD − ERROR CODE FLASHES

Troubleshooting: Heating Sequence of Operation (Continued)

CALL FOR SECOND−STAGE HEAT

2 STAGE THERMOSTAT

RECOGNITION DELAY

ONLY FOR 1ST

REQUEST FOR

2ND STAGE HEAT

CALL FOR 2ND STAGE HEAT

(HIGH FIRE)

(30 SECONDS)

EXPIRED?

YES

INDUCER SWITCHED

TO HIGH SPEED

HIGH

PRESSURE SWITCH

CLOSED WITHIN 10

SECONDS?

YES

2ND STAGE GAS VALVE

ENERGIZED

INDOOR BLOWER ENERGIZED

ON HIGH HEAT SPEED

SINGLE STAGE

THERMOSTAT

2ND STAGE

ON DELAY

EXPIRED?

YES

INDUCER SWITCHED

TO LOW SPEED

5 MINUTE DELAY

(ERROR CODE FLASHES)

CALL FOR HEAT SATISFIED

SYSTEM WILL ALWAYS LIGHT ON LOW FIIRE, EVEN IF 2ND STAGE HEAT IS IN PLACE.

WHEN USED WITH A SINGLE STAGE THERMOSTAT, SET SW1 TO THE ON POSITION IN DIP SWITCH S4.

IF THE HIGH FIRE PRESSURE SWITCH DOES NOT CLOSE WITHIN 5 ATTEMPTS, THE SYSTEM WILL OPERATE AT LOW FIRE FOR THE REMAINDER OF THE CALL FOR HEAT REQUEST.

Page 57

Troubleshooting: Heating Sequence of Operation (Continued)

CALL FOR HEAT SATISFIED

FIRST−STAGE HEAT SECOND−STAGE HEAT

2 3

RUN MODE: 1ST OR 2ND STAGE CALL FOR HEAT.

ALL INPUTS MONITORED (LIMIT, PRESSURE, CALL FOR HEAT/COOL, FLAME LEVEL)

2ND STAGE HEAT

2ND STAGE

CALL FOR HEAT

SATISFIED?

YES

DE−ENERGIZE 2ND STAGE

GAS VALVE

INDUCER SPEED SWITCHED

TO LOW SPEED

INDOOR BLOWER SWITCHED

TO LOW HEAT SPEED

1ST STAGE HEAT

1ST STAGE

CALL FOR HEAT

SATISFIED?

GAS VALVE

DE−ENERGIZED

INDUCER OFF AFTER

5 SECOND POST PURGE

INDOOR BLOWER OFF

AFTER FIELD SELECTABLE

OFF DELAY

YES

Page 58

Troubleshooting: Cooling Sequence of Operation (Continued)

CALL FOR COOLING

1ST STAGE COOLING

REQUEST RECEIVED

WAIT FOR COMPRESSOR TIMED

OFF DELAY TO EXPIRE

ENERGIZE 1ST STAGE COOLING CONTACTOR (COMPRESSOR & FAN)

INDOOR BLOWER 2 SECOND ON DELAY

ENERGIZE INDOOR BLOWER

(LOW COOLING MODE)

2ND STAGE

COOLING

REQUEST?

YES

ENERGIZE 2ND STAGE COOLING CONTACTOR (COMPRESSOR & FAN)

2ND STAGE

COOLING REQUEST

STILL ACTIVE?

MAINTAIN INDOOR

BLOWER

(LOW COOLING MODE)

YES

ENERGIZE INDOOR BLOWER

(HIGH COOLING MODE)

MAINTAIN INDOOR BLOWER

YES

1ST STAGE

COOLING REQUEST

STILL ACTIVE?

(HIGH COOLING MODE)

DE−ENERGIZE 2ND

STAGE COOLING

CONTACTOR

(COMPRESSOR & FAN)

1ST STAGE

COOLING REQUEST

STILL ACTIVE?

DE−ENERGIZE 1ST

STAGE COOLING

CONTACTOR

(COMPRESSOR & FAN)

DE−ENERGIZE INDOOR

BLOWER

YES

ENERGIZE AND MAINTAIN

INDOOR BLOWER AT

(LOW COOLING MODE)

CONTROL WILL NOT RESPOND TO A 2ND STAGE COOLING REQUEST UNLESS A 1ST STAGE COOLING REQUEST IS ACTIVE.

INDOOR BLOWER LOW COOLING MODE AND HIGH COOLING MODE HAVE SPECIFIC ON, OFF

AND SPEED RAMPING PROFILES. THE SPECIFIC PROFILE IS SELECTED USING THE

DIP SWITCHES ON THE CONROL.

Page 59

Troubleshooting: Continuous Fan Sequence of Operation

CALL FOR FAN

INDOOR BLOWER ON

CONTINUOUS FAN

SPEED

CALL FOR FAN

REMOVED?

YES

REQUEST

FOR COOLING

RECEIVED?

REQUEST

FOR HEAT

RECEIVED?

DE−ENERGIZE INDOOR

BLOWER

YES

INDOOR BLOWER OFF

MAINTAIN INDOOR

BLOWER AT

CONTINUOUS FAN

MAINTAIN INDOOR

BLOWER AT

CONTINUOUS FAN

GO TO CALL FOR COOLING

GO TO CALL FOR 1ST STAGE HEAT

Page 60

Lennox SL280DFV User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual